Fichas
AS Biology Biochemistry and Cell Structure
Fichas del conjunto (34)
- 1With reference to carbohydrates explain the difference between a CONDENSATION reaction and HYDROLYSISCondensation - when two monosaccharides join to form a disaccharide with the elimination of water and the formation of a glycosidic bond
Hydrolysis - the addition of water to a disaccharide resulting in the formation of two monosaccharides - 2State whether these carbohydrates are mono-, di- or polysaccharides and give each their role in living organisms. State whether each occurs in plants, animals or both: lactose, cellulose, glucose, glycogenLactose - di - plants - animals - energy
Cellulose - poly - plants - structure
Glucose - mono - plants - animals - energy
Glycogen - poly - animals - energy store - 3What is are ISOMERS?Compounds that have the same chemical formula but which differ in the arrangement of the atoms
- 4What does POLAR mean?Molecules that have two ends or poles that interact differently with water and fat. A hydrophilic head is attracted to water but not to fat, whereas a hydrophobic tail mixes readily with fat but is repelled by water
- 5Name the products formed and the type of bond that is broken when a triglyceride is broken downBroken down to form one molecule of glycerol and three molecules of fatty acid with the elimination of water and the breaking of an ester bond
- 6Suggest why parts of organisms that move, such as seeds, use lipids as an energy store rather than crabohydratesWhen oxidised, lipids provide more than twice as much energy as carbohydrates. If fat is stored, the same amount of energy can be provided for less than half the mass. It is therefore a lighter storage product
- 7What is meant by metabolic water?Water produced from the oxidation of food is called metabolic water. When water is scarce a camel can metabolise fats
- 8What is HYDROPHOBIC?Repels water
- 9What is HYDROPHILIC?Attracts water
- 10State two differences between a triglyceride and a phospholipidA triglyceride has three fatty acids, no phosphate group and is non-polar.
A phospholipid has two fatty acids, one phosphate group and a hydrophilic head and a hydrophobic tail - 11Which end of the phospholipid molecule lies to the outside of the membrane?The hydrophilic head
- 12State through which part of the membrane each of the following passes in order to enter or leave a cell 1) Sodium ion 2) A lipid soluble molecule1) Intrinsic protein
2) Phospholipid - 13List the four bonds present in the tertiary structure of a proteinPeptide
Hydrogen
Disulphide
Ionic - 14Classify the following proteins as fibrous or globular: insulin, collagen, keratin, lysozyme (enzyme)Insulin - globular
Collagen -fibrous
Keratin - fibrous
Lysozyme - globular - 15Why is water described as a polar molecule?A polar molecule carries an unequal distribution of electrical charge. The oxygen end has a slightly negative charge and the hydrogen end of the molecule has a slightly positive charge
- 16State the properties of water which allow the following: How are insects able to walk on water? How are fish able to live in a frozen pond? Why does sweating keep us cool?Pondskater - high surface tension
Water has a max density at 4*c so ice floats forming an insulating layer for animals below
Sweating - high latent heat - 17Why are the following properties of water important to living organisms? 1) It is a universal solvent 2) It is transparent1) To allow chemical reactions to take place in solution
2) To allow light to pass through for photosynthesis - 18What are the two major components of a virus?Core of nucleic acid
protein coat - 19What does EXOCYTOSIS mean?When a substance leaves a cell after being transported through the cytoplasm in a vesicle
- 20What does PHAGOCYTOSIS mean?The process by which the cell obtains solid materials that are too large to be taken i by diffusion
- 21The following are functions of different organelles. Name the organelle in each case: 1) Protein synthesis 2) Producing glycoproteins 3) Producing ATP 4) Produces ribosomes1) Ribosome
2) Golgi body
3) Mitochondrion
4) Nucleolus - 22Name the organelle in each case that possesses the following structures: 1) Cristae 2) Thylakoids 3) Cisternae1) Mitochondrion
2) Chloroplast
3) Endoplasmic Reticulum - 23What is a CENTRIOLE?Structure in cell division from which spindle fibres develop
- 24What is PLASMODESMATA?Strands of cytoplasm linking cells together
- 25List three features present in a plant cell, not found in an animal cellChloroplasts
Cell wall
Large permanent vacuole - 26State which of the following is a cell, tissue or organ Kidney, Epithelium, Muscle, SpermKidney - organ
Epithelium - tissue
Muscle - tissue
Sperm - cell - 27What does BIMOLECULAR mean?Phospholipid molecules stretched out to form two layers
- 28What is the difference between extrinsic and intrinsic proteins found in the cell membrane?Extrinsic proteins occur on the surface of the bilayer or partly embedded in it
Intrinsic proteins extend across both layers - 29Glucose is water soluble and vitamin A is fat soluble. They both enter a cell by passing across the membrane. Explain how the properties of the molecules and the structure of the membrane determine the way in which these two substances pass acrossVitamin A is fat soluble and freely passes through the lipid bilayer. Large molecules such as glucose are insoluble in lipids and cannot pass through the non-polar centre of the phospholipid bilayer. Intrinsic proteins assist glucose to pass in and out of the cell by facilitated diffusion
- 30State two features of the membrane that increase the rate of diffusionLarge surface area
Thin - 31Explain how an increase in temperature affects the rate of diffusionIncrease in kinetic energy of molecules results in an increase in rate
- 32How does facilitated diffusion differ from diffusionCarrier proteins are involved in facilitated diffusion
- 33State one similarity and one difference between facilitated diffusion and active transportBoth use carrier proteins; active transport requires energy/ATP; occurs against a concentration gradient
- 34Name two processes that involve active transportMuscle contraction
Nerve impulse transmission
Protein synthesis
Uptake of minerals by roots