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Description
Flashcards by lilli.atkin, updated more than 1 year ago
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Created by lilli.atkin
almost 9 years ago
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| Question | Answer |
| Why is differential centrifugation used? | To obtain organelles from cells |
| What is homogenisation? | The breaking open of cells to release organelles |
| When using differential centrifugation why is the solution; -Cold -Buffered -Isotonic | Cold- minimize enzyme activity Buffered - keep pH the same which prevents denaturing of enzymes Isotonic- keep water potential the same preventing organelles bursting/shrivelling |
| Name the organelles in order of decreasing mass | Heaviest; Nucleus Chloroplast Mitochondria Lightest; Ribosome |
| What is resolution? & Why do electron microscopes have a higher resolution? | The amount of detail that can be seen Electrons have shorter wavelength than light |
| What is the equation for magnification? | Magnification = size on paper/actual size |
| In a table list the differences between light and electron microscopes | Light; - Low resolution -Coloured image -Can be a living specimen Electron; - High resolution - Black and white image -Specimen has to be non living |
| What is the test for starch? | Add iodine solution, if present turns blue black |
| What is the test for Reducing sugar | Boil with the addition of benedict's solution If present turns brick red |
| What is the test for protein? | Add biuret solution, pale blue turns lilac if positive |
| What is the test for a lipid? | Dissolve sample in ethanol then add to water, if lipid is present water goes milky white |
| What is differentiation? | cells are specialised for a particular function |
| What is the role of; -Mitochondria -Ribosomes -Golgi apparatus -Lysosome -RER -Nucleus | Mitochondria - Aerobic respiration Ribosomes- Protein synthesis Golgi Apparatus - Packages and modifies proteins Lysosome- Contain enzymes RER -protein synthesis Nucleus - Contains DNA which carriers the code for proteins |
| What is are lipids/ carbohydrates made of? | C, H, O |
| What is protein made up of? | C, H, O, & N |
| What are 3 features of a starch molecule and the importance of each of these features? | Helical molecules - compact for storage Branched molecules - for easy hydrolysis Large molecule - Insoluble so doesnt affect water potential |
| Name the types of monosaccharides | Fructose Glucose Galactose |
| What are the reducing sugars? | Maltose Lactose |
| Do polysaccrides affect water potential? | No, as they are insoluble |
| Why are some lipids unsaturated? | Molecule contain a carbon to carbon double bond |
| What is the tertiary structure of a protein? | - further folding gives a specific surface structure e.g. an enzyme - Held by hydrogen, ionic and disuplhide bonds |
| Why are enzymes specific? | 3D tertiary structure with a specific active site |
| What can increase the rate of a reaction when a n enzyme is involved? | -Concentration of substrate; more collisions between the substrate and active site of the enzyme Temperature up to a certain point; after this point enzyme will denature -Concentration of enzyme; if increased the rate is directly proportional as long as there is an excess of substrate |
| What are the two types of inhibitors? | Competitive - by binding to the active site the inhibitor prevents the normal substrate from binding Non - competitive - inhibitor binds to site other than active site, changing the enzymes tertiary structure so the active site and substrate are no longer complementary |
| Where is Maltose digested and by what enzyme and where is that enzyme produced? | Maltose is digested in the duodenum by maltase, which is made in the pancreas to form Glucose |
| How is the ileum adapted for absorbtion? | Villi on epithelial calles creating a large surface area Single layer of cells allows for a short diffusion distance Cappliary's maintain diffusion gradient |
| How is glucose taken up into the epithelial? | Taken up by Co-transport Fits through protein cahnnel when sodium ions are attached Sodium ions are actively transported out of epithelal cells into the blood which maintains a diffusion gradient |
| What is facilitated diffusion? | Diffusion helped by carrier proteins or protien channels. Stops when a equilibrium is reached. |
| What are the stages of co-transport? | 1) Sodium pumped out of cell by active transport via the sodium/potassium pump 2) Which creates a low concentration of sodium inside the cell 3)Sodium binds to Na/glucose SYMPORT 4) When sodium binds so does glucose so transported into cell along with glucose 5) higher concentration of glucose inside cell so moves into blood by facilitated diffusion |
| Explain Lactose intolerance | A lactose intolerant person lacks lactase which breaks lactose into glucose and galactose - lactose is therefore neither digested or absorbed High levels of lactose remain in small intestine which supports large amounts of bacteria Water potential is lower in gut |
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