Back to 课程
Biology AS OCR
0% Complete
0/0 Steps
-
1-1-practical-skills-written-assessment AS7 主题
-
1-2-practical-skills-endorsement-assessment AS16 主题
-
1-2-1-practical-ethical-use-of-organisms as
-
1-2-2-practical-aseptic-techniques as
-
1-2-3-practical-dissection-of-gas-exchange-surfaces-in-fish-and-insects as
-
1-2-4-drawing-cells-from-blood-smears as
-
1-2-5-practical-investigating-biodiversity-using-sampling as
-
1-2-6-practical-data-loggers-and-computer-modelling as
-
1-2-7-practical-investigating-the-rate-of-diffusion as
-
1-2-8-practical-investigating-water-potential as
-
1-2-9-practical-factors-affecting-membrane-structure-and-permeability as
-
1-2-10-biochemical-tests-reducing-sugars-and-starch as
-
1-2-11-biochemical-tests-lipids as
-
1-2-12-biochemical-tests-proteins as
-
1-2-13-chromatography as
-
1-2-14-serial-dilutions as
-
1-2-15-practical-investigating-the-rate-of-transpiration as
-
1-2-16-practical-using-a-light-microscope as
-
1-2-1-practical-ethical-use-of-organisms as
-
2-1-cell-structure AS9 主题
-
2-1-2-using-a-microscope as
-
2-1-3-drawing-cells as
-
2-1-4-magnification-and-resolution as
-
2-1-5-eukaryotic-cells as
-
2-1-6-eukaryotic-cells-under-the-microscope as
-
2-1-7-organelles-and-the-production-of-proteins as
-
2-1-8-the-cytoskeleton as
-
2-1-9-prokaryotic-and-eukaryotic-cells as
-
2-1-1-studying-cells as
-
2-1-2-using-a-microscope as
-
2-2-biological-molecules AS17 主题
-
2-2-1-properties-of-water as
-
2-2-2-monomers-and-polymers as
-
2-2-3-monosaccharides as
-
2-2-4-the-glycosidic-bond as
-
2-2-5-polysaccharides as
-
2-2-6-biochemical-tests-reducing-sugars-and-starch as
-
2-2-7-lipids-and-ester-bonds as
-
2-2-8-lipids-structure-and-function as
-
2-2-9-biochemical-tests-lipids as
-
2-2-10-amino-acids-and-peptide-bonds as
-
2-2-11-protein-structure as
-
2-2-12-globular-proteins as
-
2-2-13-fibrous-proteins as
-
2-2-14-inorganic-ions as
-
2-2-15-biochemical-tests-proteins as
-
2-2-16-finding-the-concentration-of-a-substance as
-
2-2-17-chromatography as
-
2-2-1-properties-of-water as
-
2-3-nucleotides-and-nucleic-acids AS8 主题
-
2-4-enzymes AS9 主题
-
2-4-1-the-role-of-enzymes as
-
2-4-2-enzyme-action as
-
2-4-3-enzyme-activity-ph as
-
2-4-4-enzyme-activity-temperature as
-
2-4-5-enzyme-activity-enzyme-concentration as
-
2-4-6-enzyme-activity-substrate-concentration as
-
2-4-7-enzyme-activity-enzyme-inhibitors as
-
2-4-8-coenzymes-cofactors-and-prosthetic-groups as
-
2-4-9-practical-measuring-enzyme-activity as
-
2-4-1-the-role-of-enzymes as
-
2-5-biological-membranes AS9 主题
-
2-5-1-the-cell-surface-membrane as
-
2-5-2-membrane-structure-and-permeability as
-
2-5-3-diffusion-and-facilitated-diffusion as
-
2-5-4-practical-investigating-the-rate-of-diffusion as
-
2-5-5-active-transport as
-
2-5-6-endocytosis-and-exocytosis as
-
2-5-7-osmosis as
-
2-5-8-osmosis-in-animal-and-plant-cells as
-
2-5-9-practical-investigating-water-potential as
-
2-5-1-the-cell-surface-membrane as
-
2-6-cell-division-cell-diversity-and-cellular-organisation AS11 主题
-
2-6-1-the-cell-cycle as
-
2-6-2-the-stages-of-mitosis as
-
2-6-3-identifying-mitosis-in-plant-cells as
-
2-6-4-the-significance-of-mitosis as
-
2-6-5-the-stages-of-meiosis as
-
2-6-6-the-significance-of-meiosis as
-
2-6-7-specialised-cells as
-
2-6-8-the-organisation-of-cells as
-
2-6-9-stem-cells as
-
2-6-10-stem-cells-in-animals-and-plants as
-
2-6-11-the-use-of-stem-cells as
-
2-6-1-the-cell-cycle as
-
3-1-exchange-surfaces AS7 主题
-
3-2-transport-in-animals AS12 主题
-
3-2-1-the-need-for-transport-systems-in-animals as
-
3-2-2-circulatory-systems as
-
3-2-3-blood-vessels as
-
3-2-4-tissue-fluid as
-
3-2-5-the-mammalian-heart as
-
3-2-6-practical-mammalian-heart-dissection as
-
3-2-7-the-cardiac-cycle as
-
3-2-8-cardiac-output as
-
3-2-9-heart-action-initiation-and-control as
-
3-2-10-electrocardiograms-ecgs as
-
3-2-11-the-role-of-haemoglobin as
-
3-2-12-adult-and-fetal-haemoglobin as
-
3-2-1-the-need-for-transport-systems-in-animals as
-
3-3-transport-in-plants AS11 主题
-
3-3-1-the-need-for-transport-systems-in-plants as
-
3-3-2-the-xylem-and-phloem as
-
3-3-3-the-xylem as
-
3-3-4-the-phloem as
-
3-3-5-transverse-sections-stems-roots-and-leaves as
-
3-3-6-the-process-of-transpiration as
-
3-3-7-transpiration-in-plants as
-
3-3-8-practical-investigating-the-rate-of-transpiration as
-
3-3-9-translocation as
-
3-3-10-the-mass-flow-hypothesis as
-
3-3-11-the-adaptations-of-xerophytic-and-hydrophytic-plants as
-
3-3-1-the-need-for-transport-systems-in-plants as
-
4-1-communicable-diseases-disease-prevention-and-the-immune-system AS16 主题
-
4-1-1-common-pathogens-and-communicable-diseases as
-
4-1-2-transmission-of-communicable-pathogens as
-
4-1-3-plant-defences-against-pathogens as
-
4-1-4-non-specific-immune-responses as
-
4-1-5-phagocytes as
-
4-1-6-blood-cells as
-
4-1-7-the-t-lymphocyte-response as
-
4-1-8-the-b-lymphocyte-response as
-
4-1-9-primary-and-secondary-immune-responses as
-
4-1-10-antibodies as
-
4-1-11-opsonins-agglutinins-and-anti-toxins as
-
4-1-12-types-of-immunity as
-
4-1-13-autoimmune-diseases as
-
4-1-14-principles-of-vaccination as
-
4-1-15-sources-of-medicine as
-
4-1-16-antibiotics as
-
4-1-1-common-pathogens-and-communicable-diseases as
-
4-2-biodiversity AS10 主题
-
4-2-1-biodiversity as
-
4-2-2-sampling-to-determine-biodiversity as
-
4-2-3-practical-investigating-biodiversity-using-sampling as
-
4-2-4-measuring-species-richness-and-species-evenness as
-
4-2-5-simpsons-index as
-
4-2-6-genetic-diversity as
-
4-2-7-factors-affecting-biodiversity as
-
4-2-8-reasons-for-maintaining-biodiversity as
-
4-2-9-methods-of-maintaining-biodiversity as
-
4-2-10-conservation-agreements as
-
4-2-1-biodiversity as
-
4-3-classification-and-evolution AS15 主题
-
4-3-1-classification-of-species as
-
4-3-2-binomial-system as
-
4-3-3-classification-of-the-three-domains as
-
4-3-4-classification-of-the-five-kingdoms as
-
4-3-5-classification-and-phylogeny as
-
4-3-6-evidence-of-evolution as
-
4-3-7-types-of-variation as
-
4-3-8-standard-deviation as
-
4-3-9-variation-t-test-method as
-
4-3-10-variation-t-test-worked-example as
-
4-3-11-spearmans-rank-correlation as
-
4-3-12-adaptation as
-
4-3-13-natural-selection as
-
4-3-14-evolution-of-resistance as
-
4-3-15-consequences-of-resistance as
-
4-3-1-classification-of-species as
课 7,
主题 5
In Progress
2-5-5-active-transport as
课 Progress
0% Complete
Exam code:H020
Active Transport
-
Active transport is the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration
-
Active transport requires carrier proteins (each carrier protein being specific for a particular type of molecule or ion)
-
Although facilitated diffusion also uses carrier proteins, active transport is different as it requires energy
-
The energy is required to make the carrier protein change shape, allowing it to transfer the molecules or ions across the cell membrane
-
The energy required is provided by ATP (adenosine triphosphate) produced during respiration. The ATP is hydrolysed to release energy
A carrier protein changing shape during active transport
-
Active transport is important in:
-
The reabsorption of useful molecules and ions into the blood after filtration into the kidney tubules
-
The absorption of some products of digestion from the digestive tract
-
The loading of sugar from the photosynthesising cells of leaves into the phloem tissue for transport around the plant
-
The loading of inorganic ions from the soil into root hairs
-
Examiner Tips and Tricks
Be careful not to get carrier proteins and channel proteins confused when answering questions on active transport. Active transport requires carrier proteins (transmembrane transport proteins that undergo conformational change) not channel proteins.
Responses