paper 1 biology

explain two difference between gos and lactose

lactose contains alpha glucose whilst galactose doesn’t and gos is a polysaccharide whilst lactose is a monosaccharide

explain why amalase produced in the human digestive does not digest gos

active site is only complementary to starch not complementary to gos due to its tertiary structure

suggest why gos can work as a prebiotic

provides galactose sugar bacteria used that as a respiration bacteria uses the galactose as binary fusion

3 ways the structure of chitin is similar to cellulose

both are beta glucose and form a straight line and joined by glycosidic bonds

explain the importance of xylem being kept as a continuous tube

continuous flow of water cohesion from hydrogen bonds of all water to pull the water in the xylem it creates tension

describe how the results from the colorimeter can identify the fruit juice containing higher sugar content

higher absorbency more sugar

suggest why water potential of apple juice decreases when apple is stored

starch is hydrolysed starch is insoluble which doesn’t affect water potential so water moves into cell by osmosis

describe the transport of carbohydrates

sucrose is actively transported into phoelem cells by companion cells lowers water potential in pholem and water enters from xylem to into pholem via osmosis produces higher hydrostatic pressure mass flow to respiring cells unloaded from pholem by active transport

compare and contrast of starch and cellulose

both are polysaccharides both contain glycosidic bonds both contain carbon hydrogen and oxygen starch made up of alpha glucose cellulose is beta glucose starch is helical cellulose is straight lines cellulose has microfibrils and starch doesn’t

describe the complete digestion of starch by mammal

hydrolysis of glycosidic bonds starch to maltose by amalayse maltose to glucose by maltase

describe the relationship between fatty acid structure and fatty acid melting point

as number of double carbon carbon bonds increase melting point decrease

suggest and explain why there was more phagocytes

an increase in saturated fatty acid lead to an increase in cell surface membrane fluidity as it’s easy to engulf

suggest why fluidity of the membrane was higher after four months

phospholipids in fatty acid b is unsaturated A is an increase of saturated fatty acids has double carbon carbon bonds creates kinds so an increase in fluoride at four months

describe two functions of bikes salts

emulsify of lipids and form micelles

describe how natural selection may lead to all mammals producing feel

mutation results in new allele being formed those with new alleleles able to digest milk individuals with ceel more likely to survive and reproduce so higher proportion of this allelelen

a non complete inhibitor decreases the rate of an enzyme controlled reaction explain how

inhibitor binds to the enzyme away from the active site so active is no longer complementary fewer esc forms

what’s is a competive inhibitor

i history binds to similar shapes to the substrate comepete and binds to block active site substrate can't bond fewer esc forms

explain why the brown pigment appeared in shorter time

enzyme optimum temperature more kinetic energy increased rate of reaction

define universal overlapping and degenerate

universal is the same codon always codes for the same amino acid non overlapping is each base is only for one part of triple and degenerate is more then one codon is for each amino acid

suggest how the shape of atp allows it to have these two functions it catalyses the synthesis of ato and allows movement of h+ ions

catalyses of synthesis of atp is active site is complementary to adp+pi more esc forms and allows movement of h+ ions as channels in membrane allows facilitated diffusion

mutation result in new increase in genetic variation why

independent segregation of chromosomes crossing over between homogolpis pairs random fertilisation of gamaetes produce in new combination of alelele