Biological molecules Flashcards

Question

What is the test for a protein

Answer 1

Biuret test- blue biuret reagent turns purple if protein is present

Answer 2

Benedict’s reagent - water bath, turns orange-brown if positive

Answer 3

Iodine test - drops of iodine and shake goes blue-black if positive

Answer 4

A polysaccharide, chains of a-glucose linked by glycosidic bonds from condensation reactions

Answer 5

Short and highly branched carbohydrate

Answer 6

Animals and bacteria

Answer 7

— insoluble (doesn’t affect wp) — large + insoluble (can’t diffuse out) — compact — hydrolysed forms of a-glucose — branched

Answer 8

— insoluble — compact — more highly branched than starch

Answer 9

Made of monomers of b-glucose found in plant cell walls

Answer 10

— cellulose molecules made of b-glucose so form unbranched chains — cellulose molecular chains run parallel to each other — these molecules are grouped to form microfibrils which are grouped to form fibre

Answer 11

— they contain carbon, hydrogen and oxygen — proportion of oxygen to carbon and hydrogen is smaller than in carbohydrates — insoluble in water — soluble in organic solvents such as alcohols

Answer 12

— source of energy — waterproofing — insulation — protection

Answer 13

Three fatty acids and a glycerol

Answer 14

All linked to the maximum number of hydrogen atoms and no extra double carbon bonds

Answer 15

More than on double bond present

Answer 16

— triglycerides have a high ratio of energy-storing carbon-hydrogen bonds to carbon atoms — triglycerides have low was to energy ratio — large, non-polar and so are insoluble in water — high ratio of hydrogen to oxygen atoms

Answer 17

— 2 fatty acids — 1 phosphate — 1 glycerol

Answer 18

—hydrophilic head — hydrophobic tail

Answer 19

— polar molecules so form a bilayer — heads help hold at the surface of the cell-surface membrane

Answer 20

— molecules must collide with sufficient energy — free energy of products must be less than the substrates — may require activation energy

Answer 21

— active-site — enzyme-substrate complex

Answer 22

Substrate binds to specific active sit and enzyme slightly changes shape. Product molecules are produced so substrate is split. Enzyme the goes back to original shape.

Answer 23

— come into physical contact with its substrate — have an active site which fits the substrate

Answer 24

— formation of products — disappearance of the substrate

Answer 25

Take gradient from tangent to a curve

Answer 26

— temperature increases so kinetic energy increases — more collisions — more effective collisions so more enzyme-substrate complexes being formed — however, at around 60 degrees enzyme denatures

Answer 27

— charge on amino acid changes — substrate can no longer become attached to the active site — enzyme-substrate complex cannot form

Answer 28

As enzyme concentration increases the rate of reaction also increases until substrate concentration becomes a limiting factor.

Answer 29

If enzyme concentration is kept the Sam as substrate concentration increase rate of reaction also increases. Until enzyme concentration becomes the limiting factor.

Answer 30

— competitive inhibition — non-competitive inhibition

Answer 31

An inhibitor binds to the active site of the enzyme which means no enzyme-substrate complexes can be formed.

Answer 32

Inhibitors bind to the enzyme at other points other than the active site.