Key term
Eduqas A-Level Biology A400QS
Biological Molecules
Cell Structure and Organisation
Cell Membranes and Transport
Enzymes
Nucleic Acids and Their Functions
Importance of ATP
Photosynthesis
Respiration
Microbiology
Population Size and Ecosystems
Topic overviewPopulation growth and its measurementThe population growth curve and carrying capacityDensity dependent and density independent factorsSampling abundance and distributionEcosystems, habitats and communitiesEnergy transfer and pyramids of biomassSuccessionDecomposition and the carbon cycleThe nitrogen cycle and human interventionEutrophication and the effects of drainage
Human Impact on the Environment
Classification and Biodiversity
Topic overviewThe need for classification and the taxonomic hierarchyThe three domain and five kingdom systemsCharacteristic features of the five kingdomsAssessing relatedness by physical features and biochemistryThe species concept and the binomial systemBiodiversity, adaptation and natural selectionMeasuring biodiversity in a habitatGenetic and molecular measures of biodiversity
Mitosis and Meiosis
Sexual Reproduction in Humans
Sexual Reproduction in Plants
Inheritance
Variation and Evolution
Application of Reproduction and Genetics
Topic overviewThe Human Genome Project, other sequenced genomes and genomics in healthcareScreening embryos, stem cells and the ethical issuesGenetic fingerprinting, PCR and electrophoresis in forensic workRecombinant DNA and the production of human insulinGenetically modified crops and gene therapy
Adaptations for Gas Exchange
Topic overviewSurface area to volume ratio and gas exchange in small organismsSpecialised respiratory surfaces and the need for ventilationGills and counter current flow in bony fishThe human breathing system and its histologyVentilation and gas exchange in humansThe insect tracheal systemThe angiosperm leaf, stomata and gas exchange
Adaptations for Transport
Topic overviewVascular systems compared across animal groupsThe mammalian heart and blood vesselsThe cardiac cycle and its controlBlood, haemoglobin and dissociation curvesThe Bohr effect, chloride shift and tissue fluidThe root and the uptake of waterThe endodermis and the entry to the xylemXylem, transpiration and cohesion-tensionThe potometer and xerophytes and hydrophytesPhloem and translocation
Adaptations for Nutrition
Homeostasis and the Kidney
The Nervous System
Immunology and Disease: Disease and Its TransmissionImmunology
Immunology and Disease: AntibioticsImmunology
Immunology and Disease: The Immune ResponseImmunology
Human Musculoskeletal Anatomy: Skeletal TissuesMusculoskeletal
Topic overviewCartilage and its three typesThe composition and functions of compact boneBone remodelling and the Haversian systemRickets, osteomalacia, osteoporosis and brittle bone diseaseThe structure of skeletal muscleThe sliding filament theoryFast and slow twitch fibres, and energy for contraction
Human Musculoskeletal Anatomy: Structure and Function of the SkeletonMusculoskeletal
Human Musculoskeletal Anatomy: JointsMusculoskeletal
Neurobiology and Behaviour: The BrainNeurobiology
Neurobiology and Behaviour: NeuroscienceNeurobiology
Cell Membranes and Transport
- 6 subtopics
- 18 things to know
- Component 1
What Cell Membranes and Transport covers
Cell Membranes and Transport is one of the Core Concepts: it is taught with Component 1, Energy for Life, but may be assessed in any of the three components. It covers the fluid-mosaic model, factors affecting membrane permeability, diffusion and facilitated diffusion, osmosis and water potential, active transport and bulk transport and Determining water potential in practice.
Where it is assessed
Component 1
Energy for Life, whose Core Concepts are also assessed in the other two papers.
Check the Eduqas specification ↗The 6 subtopics
Each one has its own page.
- The fluid-mosaic modelRecall questions on the phospholipid bilayer and why it forms, what fluid and mosaic each describe, intrinsic and extrinsic proteins, cholesterol and glycoproteins, which molecules cross the bilayer directly, and why the membrane is only partially permeable.Open →
- Factors affecting membrane permeabilityThree factors that affect the permeability of a plasma membrane and how beetroot is used to investigate membrane permeability.Open →
- Diffusion and facilitated diffusionFour factors affecting the rate of diffusion, fick's law in words and facilitated diffusion.Open →
- Osmosis and water potentialWater potential, solute potential and pressure potential.Open →
- Active transport and bulk transportActive transport and secretion by exocytosis.Open →
- Determining water potential in practiceRecall questions on the change in mass and change in length methods, plotting percentage change and reading the value where the line crosses zero, blotting and the controlled variables, incipient plasmolysis, and the sources of error in both methods.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
What is facilitated diffusion, which substances need it, and why does it reach a maximum rate?
Process
Describe the steps of active transport by a carrier protein.
Key term
Name the principal components of a plasma membrane.
Key term
What is water potential?
Key term
How is the water potential of plant tissue found by change in mass?
Key term
Why do phospholipids form a bilayer in water?
Key term
Name three factors that affect the permeability of a plasma membrane.
Key term
Define diffusion.
Key term
What is the water potential of pure water?
Key term
Define active transport.
Key term
On a graph of percentage change in mass against water potential, what does the point where the line crosses zero show?
Key term
What does the word fluid describe in the fluid-mosaic model?
Key term
How does a rise in temperature affect membrane permeability?
Key term
Name four factors affecting the rate of diffusion.
Key term
Why is the water potential of a solution always negative?
Key term
Why does active transport require a carrier protein?
Key term
Why is percentage change in mass plotted rather than the change itself?
Take Cell Membranes and Transport further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
Name the principal components of a plasma membrane.
Model answer
A phospholipid bilayer, proteins, cholesterol, glycoproteins and glycolipids.
- 2
Why do phospholipids form a bilayer in water?
Model answer
Each has a hydrophilic phosphate head and two hydrophobic fatty acid tails, so the heads face the water on each side and the tails face inwards away from it.
- 3
What does the word fluid describe in the fluid-mosaic model?
Model answer
The phospholipids and many of the proteins move laterally within the layer, so the membrane is not a fixed structure.
- 4
What does the word mosaic describe?
Model answer
The proteins are scattered through the bilayer in an irregular pattern, like the tiles of a mosaic.
- 5
Distinguish an intrinsic from an extrinsic membrane protein.
Model answer
An intrinsic protein spans the bilayer, while an extrinsic protein sits on one surface of it.
- 6
Give two functions of intrinsic proteins.
Model answer
They form channels and carriers for substances that cannot cross the bilayer, and they act as pumps in active transport.
What is inside Levo
Six ways to work the same material.
Cell Membranes and Transport revision questions
- What does Cell Membranes and Transport cover in Eduqas A-Level Biology?
- 6 subtopics: the fluid-mosaic model, factors affecting membrane permeability, diffusion and facilitated diffusion, osmosis and water potential, active transport and bulk transport and determining water potential in practice. Each one has its own page with questions and model answers.
- How is Cell Membranes and Transport organised?
- By the Eduqas A400QS specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Cell Membranes and Transport, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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