Metabolism

Question 1

what is energy?

Answer 1

capacity to do work

Question 2

what is work

Answer 2

change in arrangement of matter

Question 3

how do living cells do work?

Answer 3

by transorming energy forms

Question 4

can energy exist in many forms

Answer 4

yes - kinetic, thermal…

Question 5

define: metabolism

Answer 5

sum total of biochemical reactions occuring in cells

Question 6

define: anabolism

Answer 6

building up simpler molecules into more complex ones

-requires energy (endergonic/endothermic)

Question 7

define: catabolism

Answer 7

breaking down complex molecules into simpler ones

-releases energy (exogonic/exothermic)

Question 8

what is gibbs free energy

Answer 8

energy content

Question 9

how is energy transferred?

Answer 9

through atp and redox reactions

Question 10

describe atp

Answer 10

allows energy to be cycled between catabolic and anabolic reactions
atp + h20 ADP + Pi delta G = -30.5kjmol-1

Question 11

describe phosphorylation

Answer 11

atp hydrolysed to adp and pi
pi attaches to reactant
pi and other reactant swap, enabling joining of reactants

Question 12

describe oxidatio

Answer 12

reactant loses electrons
adds oxygen and removes hydrogen
releases energy

Question 13

describe reduction

Answer 13

reactant gains electrons
adds hydrogen and removes oxygen
releases eergy

Question 14

examples of oxidation?

Answer 14

NAD+ and NADH

FAD and FADH2

Question 15

families of enzymes? (HOTILL)

Answer 15

hydrolases
Oxido-reductases
transferases
isomerases
ligases lyases

Question 16

effect of enzyme affinity on ror?

Answer 16

substrate’s attraction to enzyme

lower ea reaches same RR eventually but lower than substrate iwth higher ea

Question 17

describe enzyme inhibitors

Answer 17

• reversible: competitive and non competitive

- irreversible: poisions

Question 18

how to non competitive inhibitors work in haemoglobin

Answer 18

allosteric activator goes into allosteric site and keeps active site its functioning shape. allosteric inhibitor goes into allosteric site, changes shape of active site, lowering activity

Question 19

describe effect of competitive inhibitors on ror

Answer 19

reaches same ROR eventually but gets there more slowly

Question 20

describe effect of non competitive inhibitors on ror

Answer 20

ror tapers off lower

Question 21

describe how enzymes are regulated

Answer 21

• taking away product or adding substrates to push equilibrium forward
• change the number of enzymes (eg. when we consume more alcohol we form more alcohol dehydrogenase_
• allosteric and competitive regulation
• compartmentalisation of enzymes

Question 22

define: positive feedback

Answer 22

product of a reaction pathway stimulates an enzyme catalysing a reaction early in the sequence

Question 23

define: negative feedback

Answer 23

product of a reaction pathway inhibits an enzyme catalysing a reaction early in the sequence