People partner jobs

Are you looking for a purpose-driven role where your work directly transforms young lives? MCR Pathways is seeking a Programme Manager for our relationship-based mentoring programme in Hertfordshire and West London. We are a life-changing mentoring charity dedicated to supporting young people who have faced an unfair start in life, helping them overcome barriers and achieve their full potential.

About the role

As  Programme Manager, you'll manage, advise and support our  Pathways Coordinators in schools and other partner organisations. Your main goal is to make sure our programme is fully integrated and highly effective in schools and with partners across Hertfordshire and West London.  Although the role is remote it involves a significant amount of travel around Hertfordshire and West London so the successful candidate will need to be based within reasonable driving distance of these areas.

Key responsibilities:

• Provide support, development, training, management and motivation to MCR staff in schools and other partner organisations

• Support school integration of the programme and a consistently high quality standard of programme delivery

• Develop and support partnerships with the Local Councils, further and higher education institutions, local business and all MCR stakeholders

• Provide analysis of programme performance, impact and development

About you

• Experience of developing and effectively managing teams and programmes

• Self-motivated and skilled at motivating others

• Experience of or strong interest in working or volunteering in the third sector

• Experience of working within or in collaboration with secondary schools

• Excellent communication and presentation skills

• Attention to detail and ability to prioritise

• Experience of coordinating and analysing qualitative and quantitative data

About us

MCR Pathways is an award-winning charity established in Glasgow in 2007.  We currently support over 7,800 young people across the UK who’ve had an unfair start in life, through our community of mentors, donors, staff, and partners. They are united by a shared belief: that every young person deserves someone to help them find their way. We believe in the power of mentoring and that a single connection can change a life.

We connect young people with volunteer mentors who offer support, encouragement and a listening ear. The aim is to empower young people to define their own ambitions, supporting them from aspiration to achievement. It’s more than academic success; it’s about instilling belief, resilience and the chance to thrive.

Mentoring is at the heart of what we do, but not all we do. We create opportunities like career tasters, job shadowing, and work experience helping young people access networks and pathways they might not otherwise reach. We support them into further and higher education, apprenticeships and employment and fulfilling careers helping them live their best life.

MCR Pathways’ values are Respect, Communication, Trust and Growth and they inform everything we do.

A part-time role developing, curating, delivering and finessing training for two distinct audiences – training for those who have low digital confidence, as well as young people, in how to use digital devices effectively and efficiently; and also training for those who may come into contact with, or wish to learn about, digital poverty, including staff of corporates and community providers. 

The former audience – learning about digital skills – will need to gain knowledge and understanding about the foundational elements of using laptops, tablets and smartphones.  This includes Essential Digital Skills such as setting passwords, connecting to Wi-Fi and using keyboards, as well as soft skills such as staying safe online, critical thinking and recognising fake news or AI generated imagery.

The latter audience – learning about digital poverty – will need to learn about the causes and impacts of digital poverty, what impact digital exclusion has on families and communities, and how to understand if someone is digitally included.

There may be other training requirements as well – such as training external users of our systems, training corporate volunteers, or a train-the-train model of supporting young people to work with those in their communities.

Key responsibilities

• Work with CEO and SMT to gain a strong understanding of the content we wish to deliver.
• Design a range of standardised training materials, developing curriculum plans, which are able to be tailored easily for cohorts.
• Work with the Head of Development to ensure training meets the needs of potential partners.
• Work with delivery and project officers to understand training requirements as they relate to specific programmatic requirements.
• Deliver training as the lead trainer for the charity, usually in person but sometimes online.
• Work with partner organisations to build strong relationships, especially when working with corporate volunteers.
• Create and implement monitoring and evaluation frameworks to assess the effectiveness of the training, gather feedback and finesse the training models you have created.
• Be able to run a train the trainer model for corporate volunteers, other staff, and young people on specific programmes, briefing them and ensuring consistency and quality.
• Work with the Head of External Affairs to produce high quality materials, including presentations, leaflets and other resources.
• Support marketing, project management, contract management and other functions delivered by other team members.
• Provide accurate reporting on the basis of feedback, participation and other indicators of current success.
• Take a self-sufficient approach to logistical management, whilst also working with colleagues where duties overlap.
• Keep up to date on developments in digital skills, maintaining subject matter knowledge.
• Maintain a strong understanding of the digital poverty landscape, including across policy, research and interventions, to inform training delivery.
• Work with colleagues to role model best practice in training.

The role is remote based - the whole team works from home - but you will need to be able to regularly travel across the UK including potential overnight stays and evening working.  You must feel comfortable being the person who sets up at a training event, and have a hands-on approach.  (The costs of travel are, of course, covered.)

Principal responsibilities:

1. To develop, deliver and provide a range of IAA and community wellbeing activities and services, to meet the needs of people mental health problems 

2. Provide IAA and community well-being services that comply with relevant legislation particularly social services and well-being (Wales closed) act 2014

3. Promote early detection and early resolution, so that concerns and problems are put right quickly and effectively

4. Contributes towards preventing the development of people's need for care and support

 Expectations

1. Maintain confidentiality at all times

2. To attend a contribute to the Mind in Gwent’s supervision and appraisal process

3. To attend, and contribute to, Mind in Gwent’s team meetings and annual planning meetings and other meetings as necessary

4. To attend and contribute to Mind in Gwent’s staff training as required

5. To abide by all of Mind in Gwent’s policies

6. To contribute to a positive and supportive working environment

7. To contribute to making Mind in Gwent a greener workplace

8. To uphold the values of Mind in Gwent and be a champion for Mind in Gwent at all times

9. To support and contribute to our overall aim of the participation of people with experience of mental health problems

10.  This post is based in Newport and at times the post holder may be required to provide services at weekends and in the evenings as well as from other Mind in Gwent sites, then use of partner or community organizations, as well as to provide cover for other staff and services.

We’re looking for a passionate and experienced leader to head our sector support and grants team (maternity cover). You’ll bring strong project and people management skills, a commitment to social justice, and a track record of delivering impactful support to external partners. With experience in funder plus support, grant-making, and stakeholder engagement, you’ll help legal advice agencies thrive. This is a high-impact role guiding the development of our sector support programmes to ensure we best meet the needs of organisations providing vital legal help to those most in need. You’ll lead a small, dedicated team and work collaboratively across the organisation to deliver meaningful change.

See attached Recruitment Pack for more details.

We’re an award-winning charity that runs local learning centres in the heart of communities where the young people we support live. Our centres provide an innovative education programme which includes practical learning support and motivational and confidence-building activities for children and young people aged 7-18. Our aim is to inspire students from the least advantaged neighbourhoods to broaden their horizons and achieve their full potential.

As the UK’s leading university access organisation, our staff team is helping thousands of young people each year. We have forty-four centres and extension projects across England and Scotland, with ambitious plans to scale-up our provision further over the coming years.

We are looking for individuals who will thrive in a fast-paced, rewarding role helping to change the lives of young people by taking up a permanent role as a part-time Programme Support Tutor. You will work closely with our existing team, supporting the delivery and organisation of the IntoUniversity programme in the centre.

The main duties of the role

To deliver the IntoUniversity programme effectively to children and young people in different settings, including schools-based workshops, Academic Support sessions and educational visits. This includes positive behaviour management and adherence to the IntoUniversity safeguarding policy.

• To assist with the organisation and delivery of the Academic Support, FOCUS and Mentoring Programmes.
• To assist the IntoUniversity Centre Leader in liaising with schools and other partner bodies, in organising the classroom and resources and in planning project delivery. 
• To update and maintain IntoUniversity displays, publicity and resources.
• To work with the IntoUniversity Centre Leader to recruit children and young people to the programme, including after-school Academic Support and FOCUS Weeks. 
• To develop educational resources and worksheets for use across all IntoUniversity programmes. 
• To ensure compliance with all necessary regulations and legal requirements, including the Children’s Act,  Children and Young People (Scotland) Act, Safeguarding Vulnerable Groups Act, Protection of Vulnerable  Groups (Scotland) Act, and legislation and policies related to Equal Opportunities and Health & Safety. 
• To champion diversity and inclusion in your role at all times, referring to the Diversity and Inclusion Staff Responsibilities Guide. 
• To undertake any task that may be requested from time to time that may be consistent with the nature and scope of this post. 

Contract
Permanent, part-time

Start date

Monday 1st September 2025 (in line with local school term)

Working hours

• 15 or 16 hours per week (please see job description for further information).

Salary

Starting salary is £28,250 (pro-rata).
Pro-rated salary is £10,885 per annum for 16 hours per week.
Pro-rated salary is £10,205 per annum for 15 hours per week.

Location
IntoUniversity Clacton

Staff benefits

• Employee Assistance Programme including access to wellbeing and legal support 
• Life Assurance scheme with AIG including SmartHealth service with access to 24/7 online GP appointments 
• Staff in FOCUS – rewards, competitions and prizes across the year 
• Interest-free new starter loans of up to £1,000 
• Cycle to Work Scheme and Travelcard Loan Scheme 
• Employer pension contributions of 6% 
• Staff in FOCUS – rewards, competitions and prizes across the year

At Ambitious about Autism we're currently looking for a Community Fundraising Manager to join our Fundraising team.

You'll be the driving force behind the growth and success of this important income stream. You will inspire the communities in which we work to make a meaningful difference to the lives of autistic children and young people. You will have proven experience of exceptional relationship management and be able to think creatively to inspire community groups, schools, individuals and local businesses.

You'll develop and implement community fundraising strategies and identify, approach and cultivate relationships with community groups, schools, local businesses and individuals. Community Fundraising will play a key role in successfully delivering Ambitious about Autism's wider 2025-28 Fundraising Strategy. We are looking for a passionate self-starter with exceptional relationship building skills that feels excited at the prospect of shaping the future of Community Fundraising at Ambitious about Autism.

We are looking for someone who has:

• Experience of building and growing Community Fundraising income
• Experience of developing and delivering fundraising strategies
• Experience of planning and implementing successful Community Fundraising programmes including setting and meeting financial and supporter cultivation targets
• Excellent planning, project management and organisational skills

In return, we offer great benefits including a generous holiday allowance and commitment to continued professional development (CPD), flexible, hybrid working and more!

This is a fantastic opportunity for an ambitious individual who would like to work for a forward-thinking, open and honest organisation and make a real impact to the young people we work with. Please find our full recruitment pack on the link below.

If you have any questions about the role or would like to have a confidential chat, please contact James Axford, Recruitment Officer.

Ambitious about Autism is committed to fostering equity, diversity, and inclusion at every level of our organisation. We warmly welcome applications from all qualified candidates, valuing the diverse backgrounds, experiences, and perspectives they bring. We encourage applications from individuals regardless of race, colour, nationality, ethnic or national origins, religion or belief, sex, sexual orientation, gender identity or expression, marital or civil partnership status, pregnancy or parental status, disability, or age.

Our recruitment process promotes equal opportunities, and we are committed to providing reasonable adjustments for candidates with disabilities or additional needs throughout the recruitment process. Please contact our Recruitment Team for accommodations. We recognise disability as a physical or mental impairment that significantly and long-term affects a person's ability to perform day-to-day activities, as defined by the UK Equality Act 2010. All applications will be considered solely on merit, aligned with our mission to support autistic children and young people.

Ambitious about Autism is committed to safeguarding and promoting the welfare of children and young people and successful candidates will be subject to an Enhanced DBS check. As part of our Safer Recruitment checks, an online search maybe carried out in line with Keeping Children Safe in Education.

The Safeguarding responsibilities of the post as per the job description and personal specification.
Whether the post is exempt from the rehabilitation of Offenders Act 1974 and the amendment to the Exceptions Order 1975, 2013 and 2021. This means that when applying for certain jobs and activities certain spent convictions and cautions are ‘protected', so they do not need to be disclosed to employers, and if they are disclosed, employers cannot take them into account. Further information about filtering offences can be found in the DBS Filter Guidance.

Are you passionate about creating real change for young people across Wales?
Do you thrive on building strategic partnerships, influencing policy, and driving impactful education programmes? If so, we’ve got an exciting opportunity for you to lead the charge as our Wales Lead at Young Enterprise—a role where you’ll be the face of our mission, championing financial and enterprise education where it’s needed most.

Who We Are
We’re Young Enterprise – a national charity with a bold mission: to give every young person the skills, confidence, and mindset to thrive in the changing world of work.

For over 60 years, we’ve empowered more than 7 million young people through hands-on enterprise and financial education programmes. Whether it’s launching a student business or learning how to manage money, we help young people develop key life skills—teamwork, leadership, problem-solving, and resilience.

We’re a passionate, down-to-earth team of 90+ staff and 2,000+ volunteers who believe that every young person, regardless of background, deserves a fair start in life.

Why Join Us?
We think Young Enterprise is a great place to work—and we’re proud of our people-first culture. Here’s what you can expect:

 · A friendly and supportive team where your voice is heard

· A strong commitment to diversity and inclusion—we want everyone to feel they belong

· Generous holiday allowance and flexible working

· Cycle-to-work scheme, life assurance, and NHS top-up plan

· Ongoing learning and mentoring opportunities

· A chance to directly impact the lives of young people every single day

About the Role
As our Wales Lead, you’ll take on a high-impact, strategic role at the forefront of creating real change for young people across Wales. You won’t just be shaping our vision—you’ll be bringing it to life by building powerful partnerships, influencing key decision-makers, and championing the growth of our enterprise and financial education programmes in the places they’re needed most.

 This role is anything but ordinary. One day you could be speaking at a roundtable in the Senedd, the next you might be rallying new corporate partners, supporting a school’s first enterprise challenge, or welcoming a team of volunteers to inspire students during a school workshop. You’ll be a connector, an ambassador, and a changemaker—leading the charge to embed our work into Welsh policy and priorities while forging strong, purposeful relationships across Welsh Government, local authorities, schools, and community organisations.

 You’ll be the face and voice of Young Enterprise in Wales—energising a wide network of businesses, educators, funders, and volunteers to scale our impact and amplify our reach. With a strong focus on growth, fundraising, and influence, you’ll help us secure the resources and recognition needed to empower young people with the skills, confidence, and resilience they need for life, work, and the future.

We're especially keen to hear from candidates who are bilingual in Welsh and English, as this is a great asset for the role.

You’ll love this job if you are…

· A brilliant relationship-builder, confident working senior-level stakeholders and has a solid understanding of the political and policy landscape in Wales

· Excited by the idea of a fast paced varied role that will be truly transformational for young people in Wales

· Passionate about education, social mobility, and giving every young person a chance to shine

· A natural communicator—whether talking to Government, supporters, schools or young people

· Organised and able to juggle multiple projects (with a great sense of humour!)

· Self-motivated, adaptable, and happy working remotely but never alone—you’ll be part of a close-knit team

Key Responsibilities

· Lead the strategic growth of Young Enterprise in Wales

· Lead on policy awareness, ensuring the organisation remains responsive to Government priorities and commissioned reports

· Develop, maintain and lead strategic relationships with key stakeholders, including funders, local and national government, education bodies and partners

· Identify and secure  funding to support our work across Wales with an ambitious focus on growing income

· Deliver and support the rollout of YE programmes in schools and other settings

· Recruit, train and support volunteers—making sure they feel valued and inspired

· Represent YE in Wales externally at events and forums, promoting the organisations profile and influence across the education and third sector

· Focus your energy on reaching young people who face the greatest barriers to opportunity, making sure our work has the biggest impact where it’s needed most

· Build strong partnerships with businesses, educational settings and other local organisations to bring our programmes to life in both formal and informal settings

· Keep accurate records, track impact, and make sure safeguarding is front and centre

A few practical things:

· This is an active hands-on role—you’ll sometimes be lifting resources, setting up venues and travelling regularly (a car and full driving licence are essential)

· You’ll need to be a prolific networker, keen to develop new relationships across Wales to expand our reach

· You’ll need to be happy occasionally working evenings or weekends during peak delivery times

· Expect to be on your feet during some events or sessions—it’s all part of the fun!

Safeguarding Young People
We are committed to keeping young people safe. All successful applicants will undergo an enhanced DBS check and receive ongoing safeguarding training.

How to Apply
If you’re ready to help shape the futures of young people across Wales, we want to hear from you!

Please send your CV and a cover letter (max 2 pages) telling us why you’re the right person for this role. Applications must be submitted by 23:30 on 21 August 2025. Please note that applications without a cover letter will not be considered.

Interviews will be conducted via Teams, and we may shortlist and invite candidates to interview before the closing date. Please note, we are only able to respond to shortlisted candidates.

At YE we are passionate and committed to keeping your data safe and secure. Full details can be found in the YE People’s Privacy Notice.

Join us – and help us give every young person the chance to thrive Apply today!

About UP

Unlocking Potential deliver high performing therapeutic programmes and education provision for children and young people with SEMH needs. We work in collaboration with families, communities, and other partners to ensure that children and young people access the interventions they need to thrive.

Mission

We work collaboratively with communities to enable children and young people with social, emotional, and mental health needs to unlock their full potential

Values

Trust

We build trust by being honest, transparent, and accountable in the way we work with children and young people, staff, and partners and by providing services and programmes whose outcomes are measurable and evidenced based.

Collaborative

Relationships are at the heart of our work. We prioritise communication and collaboration with partners, families, and communities, believing that by working together we create more effective and holistic outcomes for children and young people.

Empowering

We co-create opportunities for our children, young people, parents/carers and staff to actively participate in decision-making that influences change. We promote the voices of children and young people in our organisation and the wider community.

Nurturing

We provide a nurturing approach based on safety and space for creativity, exploration, and growth. We support and care for our children, young people, and staff to realise their potential.

Impact

We are committed to measuring our impact through a data driven method to develop our programmes and make a greater difference to the lives of children, young people, and their parents and carers.

Overview

We will be launching our new programme from September 2025, initially as a pilot working with families across Wandsworth, with aims to be able to expand and continue beyond this.

As a Family Support Worker, you will deliver flexible, hands-on, and therapeutically minded support to families facing multiple and complex challenges. You will build trusted relationships through home visits, school meetings, and practical support—empowering parents and carers to strengthen routines, manage behaviour, improve attendance, and access services. Your role will be guided by detailed needs assessments and focused on achieving meaningful outcomes with each family.

As Delivery Officer (Communities and Opportunities), you’ll play a key role in empowering over 570 young Londoners—particularly those from underrepresented backgrounds—through structured volunteering and social action. Working with 15 grassroots partners, you’ll support programme delivery, youth engagement, and inclusive events that amplify youth voice and leadership. You’ll help ensure smooth day-to-day operations, contribute to wider team goals, and receive regular support to grow in your role. Join the Mayor’s Fund for London and help shape a fairer, more inclusive city for young people.

Job Title: Experienced Associate Independent Investigating Officers (IOs) for Stage 2 Complaints (This role sits within our Independent Person for Complaints (IPC) service)

Contract: Associate

Hours: Variable, according to demand for services/caseload and role in investigation

Salary: £25.25 per hour

Location: Associate Independent Investigating Officers for Complaints primarily work from home. Some travel may be required as part of an investigation – location will vary according to the referral received from the Local Authority. Cases will be allocated to Associate IOs living locally to the referring authority, wherever possible.

About Coram

Coram is committed to improving the lives of the UK’s most vulnerable children and young people.

We support children and young people from birth to independence, creating a change that lasts a lifetime.

Coram is the UK’s oldest children’s charity, founded by Thomas Coram in London, helping vulnerable children and young people since 1739. Today, the Coram group helps more than one million children, young people, families and professionals every year by providing access to the skills and opportunities they need to thrive.

About the role

We are seeking additional experienced Associate Independent Investigating Officers (IO) for Complaints, to increase our capacity to respond to referrals from Local Authorities to provide an independent element to the formal Stage 2 investigations under the Children Act 1989.

The IO will lead investigations, and will give the complainant (who may be a child, young person or adult) the opportunity to express their view, ensure the child or young person’s rights and best interests are at the centre of the investigation and that the investigation/review process is open and transparent. They write a report on the investigation/review, which is submitted to the referring agency.

The Job Description document sets out the expectations for an Associate Independent Person for Complaints (IPC) who is approved by Coram Voice. IPCs are independent, freelance and responsible for their own work. Nevertheless, IPCs are accountable to the organisation for their professional standards and are expected to comply with Coram Voice Code of Ethics and Practice Guidelines.

Please note: the nature of associate work means that we cannot guarantee a regular amount of work, and complaints will be allocated dependent on the associate’s availability, location and the needs and demands of the individual case. Investigation work takes place Monday to Friday within working hours. This position is not suitable for applicants who already work or have commitments more than two days within the working week.

To apply for this role, please click on the 'apply now' button below to complete the application.

Closing date: Please note this is a rolling recruitment campaign

Interview date: TBC

Coram is an equal opportunities employer and we believe a diverse workforce enables us to improve the services to the children and families we help. We are genuinely committed to encouraging candidates from all sections of the community we seek to support. This includes those from, Asian, African, Caribbean and other minority ethnic backgrounds, those that identify as LGBTQ+, those with disabilities, those with lived experience of care, those with neuro-diversity, and those from other groups who are underrepresented at Coram.

If applicants feel comfortable, we would encourage them to draw on lived experience as well as professional experience in their personal statement as part of their application.

We are committed to the safeguarding of children and where appropriate will require the successful applicant to undertake a check from the Disclosure and Barring Service.

Registered Charity No. 312278.

Are you passionate about people with lived experience of the justice system being at the forefront of its ongoing design and improvement? Do you want to play a pivotal role in successfully promoting and raising funds for our charity that puts lived experience front and centre of its leadership, operations and influencing work?

User Voice is a pioneering charity that works with people with convictions to support and develop their confidence, skills and mindsets. They then deliver our programmes to many more people who are impacted by the criminal justice system.

80% of our staff have convictions, meaning we’ve been there – in court, in prison, or on probation – we own our own pasts, so we understand the challenges first hand and use our own lived expertise to inform everything we do.

This exciting role will involve coordinating communications to promote our work and engage stakeholders, and assisting in the development and implementation of plans to secure financial support for the charity, by aligning fundraising and communication strategies.

BVSC are members of a local consortium where eight voluntary sector organisations have come together to support local people with care and support needs in new and sustainable ways.  The consortium will work as “Trusted Partners” to enable people to find the right support services that meet their needs and fulfil their personal goals – supporting them to maintain their independence for as long as possible and helping them to plan ahead. 
 

The consortium service requires a role to act as a single point of access where consortium partners, residents, referrers, and adult social care can contact for information and access to the service. The service is operational from 9am-5pm Monday to Friday and the single point of access will provide the intermediary between LA/Consortia for day today queries and will monitor referrals into the consortium.

 

Who you are

• You are someone who shares and can mobilise the charity's values of Independence, Empowerment, Partnership, Professionalism, Staff Recognition, and Sustainability. If you have knowledge, application, and commitment to these values, we want to hear from you.
•  
• You are someone with experience of or a commitment to developing a person-centred approach in working with people with complex needs and challenges.

• . Your values and working practice will align with those of the charity to maximise the independence of those you are working with; to enable their ability to make decisions about the types of service they receive of and to ensure that your approach is both professional and sustainable.

Who we are

At Balance we are committed to empowering those we support to build independence, fulfilled and self-confident lives.  We work hard to ensure our charitable values are central to the professional experience of those who work for us, with us and who benefit from our services. 

Main Responsibilities of the Job
.

• To demonstrate Balance values of partnership, independence, professionalism, empowerment, staff recognition, and sustainability in your conduct and approach to your work
• Through partnership, support and develop people's skills, confidence and interests as part of a multi-disciplinary day service offer.
• To support your colleagues, service managers, and other key professionals to put those using our service at the centre of your daily work.
• To maintain and update client and related operational records with an accurate and professional commitment.
• To ensure compliance with and the delivery of the charity's policies and procedures, particularly those related to safeguarding, inclusion, and disability discrimination.
• To support clients with their daily activities and to promote their independence
• To be able to communicate effectively with families, colleagues and clients.

Working Expectations

• The working day is  9 am - 4 pm Monday to Friday - 
• Attendance at training.
• Use of information technology to support your work.

Benefits of Working for us

The charity ensures the following benefits for all its operational staff:

• A baseline commitment to pay the London living wage for all its front line staff.
• A commitment to training and professional development to support internal progression as part of our performance support.
• Inclusion in and contribution to the charity's pension scheme.
• Generous annual leave allowance of 25 days a year plus an additional day off for your birthday.
• Access to a range of discount schemes.
• Access to the charity's employee assistance programme.
• Access to travel card, loan, and bike to work scheme.

 
Please note we do not accept applications from Overseas

Benefits

A baseline commitment to pay the London living wage for all its front-line staff.
A commitment to training and professional development to support internal progression as part of our performance support.
Inclusion in and contribution to the charity's pension scheme.
Generous annual leave allowance of 25 days a year, plus an additional day off for your birthday.
Access to a range of discount schemes.
Access to the charity's employee assistance programme.
Access to travel card, loan, and bike to work scheme