Understanding biochemistry is like having a toolkit for analysing life...
Biology350 views·Updated 13 Jul 2026·2 pagesAS Level Biology 1.1: KEY Topics Explained - WJEC
Kat bert@katbert
1
of 2
Biochemical Tests and Water Properties
You'll need to master four key biochemical tests for your exams. Starch turns blue-black with iodine solution, whilst proteins change from blue to purple with biuret reagent. For lipids, mix with ethanol then water - a cloudy emulsion means lipids are present.
Reducing sugars create a colour spectrum with Benedict's reagent, from blue (no sugar) through green, yellow, orange to brick-red (loads of sugar). Non-reducing sugars need boiling with hydrochloric acid first to break them down.
Water's unique properties make life possible. Its high surface tension creates habitats, whilst high specific heat capacity keeps cellular conditions stable. The fact that ice floats protects aquatic life underneath, and water's cohesive properties allow it to be pulled up through plant stems.
Quick Tip: Remember the acronym CHILIS for water properties - Colourless, High surface tension, High latent heat, High specific heat, Ice floats, Liquid at room temp, Strong cohesion!
2
of 2
Protein Structure and Lipid Functions
Protein structure has four levels you must understand. Primary structure is simply the amino acid sequence, whilst secondary structure involves hydrogen bonding creating repeating patterns like alpha-helices. Tertiary structure gives the final 3D shape through various bonds and interactions.
Globular proteins fold into spherical shapes and dissolve in water (like haemoglobin), whereas fibrous proteins remain long and parallel, usually insoluble (like collagen). Quaternary structure involves multiple polypeptide chains working together.
Lipids serve three main functions: insulation, energy storage, and protection. Triglycerides combine glycerol with three fatty acids, whilst phospholipids have just two fatty acids plus a phosphate group, creating molecules with hydrophilic heads and hydrophobic tails.
Exam Focus: Van der Waals forces occur because electrons move constantly, creating temporary positive and negative areas that help molecules stick together - this often appears in extended response questions!
We thought you’d never ask...
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar content
Most popular content: Proteins
5BiologyA-Level Biology Active Recall
Enhance your understanding of A-Level OCR Biology with this comprehensive active recall resource. Covering key concepts such as cell structure, enzyme function, and ecological interactions, this study material is designed to reinforce your knowledge and improve exam performance. Ideal for revision and self-assessment.
1267312
BiologyUnderstanding Protein Structures
Explore the four levels of protein structure: primary, secondary, tertiary, and quaternary. This detailed summary covers key concepts such as peptide bonds, hydrogen bonds, and the differences between globular and fibrous proteins. Ideal for A Level Biology students preparing for exams.
12881
BiologyBiological Molecules Overview
Explore the essential concepts of biological molecules, including DNA replication, protein structure, and the roles of carbohydrates and lipids. This comprehensive summary covers key processes such as semiconservative replication, enzyme functions, and the significance of nucleotides in nucleic acids. Ideal for OCR A Level Biology students, this resource aligns with the 2016-onwards specification and provides a clear understanding of molecular biology fundamentals.
1243813
BiologyTOPIC 1: A-Level Biology
Topic 1 (Biological Molecules, More Biological Molecules) for A-Level Biology
121123
BiologyProteins
Paper 1. What is a protein? What it’s structure? What are types of bonding involved? How to test for proteins? Globular VS Fibrous. Haemoglobin VS Collagen.
12673
Most popular content in Biology
9C
BiologyCell Biology and Cell structure
cell structures
93,2800
T
BiologyThe functions of subcellular structures - B1 Biology
Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.
102,8215
1
Biology1.cells Gcse biology question cards
combined science higher biology
92,3634
BiologyAQA Biology: Key Concepts
Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.
108,871308
B
BiologyBiology Paper 1 quiz
this is a simple quiz on key knowledge needed for paper 1
102,7825
T
BiologyTypes of cells
biology
101,2170
BiologyA-Level Biology Year 1 Overview
Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
1214,924697
Biologybiology paper 1
all notes
102,47737
B
Biologybiology paper 1
these are some exam questions for biology paper which are more likely to come up in exams
101,8040
Most popular content
9
SociologySociology of Education Overview
Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.
12102,9583,041
SociologySociology of Families: Comprehensive Revision
Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.
1273,7512,307
CriminologyCriminology: Crime & Punishment Overview
Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.
1254,8931,060
SociologyComprehensive Crime & Deviance Overview
Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.
1251,6691,400
C
BiologyCell Biology and Cell structure
cell structures
93,2800
CriminologyWJEC Unit 4 Criminology
Criminology unit 4 detailed revision note
127,176125
SociologySociological Theories Overview
Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.
1231,479846
T
BiologyThe functions of subcellular structures - B1 Biology
Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.
102,8215
1
Biology1.cells Gcse biology question cards
combined science higher biology
92,3634
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user
Biology350 views·Updated 13 Jul 2026·2 pagesAS Level Biology 1.1: KEY Topics Explained - WJEC
Kat bert@katbert
Understanding biochemistry is like having a toolkit for analysing life itself - these fundamental tests and molecular structures form the backbone of A-level Biology. From identifying what's in your food to understanding how proteins fold, these concepts will pop up...
1
of 2
Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Biochemical Tests and Water Properties
You'll need to master four key biochemical tests for your exams. Starch turns blue-black with iodine solution, whilst proteins change from blue to purple with biuret reagent. For lipids, mix with ethanol then water - a cloudy emulsion means lipids are present.
Reducing sugars create a colour spectrum with Benedict's reagent, from blue (no sugar) through green, yellow, orange to brick-red (loads of sugar). Non-reducing sugars need boiling with hydrochloric acid first to break them down.
Water's unique properties make life possible. Its high surface tension creates habitats, whilst high specific heat capacity keeps cellular conditions stable. The fact that ice floats protects aquatic life underneath, and water's cohesive properties allow it to be pulled up through plant stems.
Quick Tip: Remember the acronym CHILIS for water properties - Colourless, High surface tension, High latent heat, High specific heat, Ice floats, Liquid at room temp, Strong cohesion!
2
of 2Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Protein Structure and Lipid Functions
Protein structure has four levels you must understand. Primary structure is simply the amino acid sequence, whilst secondary structure involves hydrogen bonding creating repeating patterns like alpha-helices. Tertiary structure gives the final 3D shape through various bonds and interactions.
Globular proteins fold into spherical shapes and dissolve in water (like haemoglobin), whereas fibrous proteins remain long and parallel, usually insoluble (like collagen). Quaternary structure involves multiple polypeptide chains working together.
Lipids serve three main functions: insulation, energy storage, and protection. Triglycerides combine glycerol with three fatty acids, whilst phospholipids have just two fatty acids plus a phosphate group, creating molecules with hydrophilic heads and hydrophobic tails.
Exam Focus: Van der Waals forces occur because electrons move constantly, creating temporary positive and negative areas that help molecules stick together - this often appears in extended response questions!
We thought you’d never ask...
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar content
Most popular content: Proteins
5BiologyA-Level Biology Active Recall
Enhance your understanding of A-Level OCR Biology with this comprehensive active recall resource. Covering key concepts such as cell structure, enzyme function, and ecological interactions, this study material is designed to reinforce your knowledge and improve exam performance. Ideal for revision and self-assessment.
1267312
BiologyUnderstanding Protein Structures
Explore the four levels of protein structure: primary, secondary, tertiary, and quaternary. This detailed summary covers key concepts such as peptide bonds, hydrogen bonds, and the differences between globular and fibrous proteins. Ideal for A Level Biology students preparing for exams.
12881
BiologyBiological Molecules Overview
Explore the essential concepts of biological molecules, including DNA replication, protein structure, and the roles of carbohydrates and lipids. This comprehensive summary covers key processes such as semiconservative replication, enzyme functions, and the significance of nucleotides in nucleic acids. Ideal for OCR A Level Biology students, this resource aligns with the 2016-onwards specification and provides a clear understanding of molecular biology fundamentals.
1243813
BiologyTOPIC 1: A-Level Biology
Topic 1 (Biological Molecules, More Biological Molecules) for A-Level Biology
121123
BiologyProteins
Paper 1. What is a protein? What it’s structure? What are types of bonding involved? How to test for proteins? Globular VS Fibrous. Haemoglobin VS Collagen.
12673
Most popular content in Biology
9C
BiologyCell Biology and Cell structure
cell structures
93,2800
T
BiologyThe functions of subcellular structures - B1 Biology
Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.
102,8215
1
Biology1.cells Gcse biology question cards
combined science higher biology
92,3634
BiologyAQA Biology: Key Concepts
Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.
108,871308
B
BiologyBiology Paper 1 quiz
this is a simple quiz on key knowledge needed for paper 1
102,7825
T
BiologyTypes of cells
biology
101,2170
BiologyA-Level Biology Year 1 Overview
Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
1214,924697
Biologybiology paper 1
all notes
102,47737
B
Biologybiology paper 1
these are some exam questions for biology paper which are more likely to come up in exams
101,8040
Most popular content
9SociologySociology of Education Overview
Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.
12102,9583,041
SociologySociology of Families: Comprehensive Revision
Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.
1273,7512,307
CriminologyCriminology: Crime & Punishment Overview
Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.
1254,8931,060
SociologyComprehensive Crime & Deviance Overview
Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.
1251,6691,400
C
BiologyCell Biology and Cell structure
cell structures
93,2800
CriminologyWJEC Unit 4 Criminology
Criminology unit 4 detailed revision note
127,176125
SociologySociological Theories Overview
Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.
1231,479846
T
BiologyThe functions of subcellular structures - B1 Biology
Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.
102,8215
1
Biology1.cells Gcse biology question cards
combined science higher biology
92,3634
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user