metabolic pathways

Question 1

what is human metabolism?

Answer 1

it can acquire and utilize the free energy they need to carry out their various functions

Question 2

_____ ______ need to be complex because cells need to use energy efficiently

Answer 2

metabolic pathways

Question 3

what is the 3 step process for carrying out a metabolic pathway

Answer 3

1. physical separation, soluble enzymes with diffusing intermediates
2. A multienzyme complex, substrate enters the complex and becomes bound, then product is released
3. a membrane-bound multienzyme system

Question 4

the main phase of glucose oxidation 1, what is this?

Answer 4

this oxidation in the cell results in the formation of more than 30 molecules of ATP

Question 5

what is the first phase of oxidation

Answer 5

glycolysis

Question 6

what does the first phase of oxidation result in ?

Answer 6

formation of 2 C3 fragments

Question 7

what happens in the second phase of oxidation

Answer 7

C3 fragments are oxidised to carbon dioxide and water within the mitochondria

Question 8

what happens in the third phase of oxidation

Answer 8

the energy from the re-oxidation of reduced carriers is used to generate ATP

Question 9

in animals what can glucose be converted into? and what can it be used for

Answer 9

acetyl CoA
synthesise fats

Question 10

what can’t be converted into glucose?

Answer 10

acetyl CoA
hence the fatty acids cannot be used to make glucose

Question 11

what happens in gluconeogenesis

Answer 11

pyruvate is converted to glucose
hence the amino acids which give rise to pyruvate and can be used to make glucose

Question 12

during a sprint, when ATP needs outpace oxygen delivery, glucose….

Answer 12

is metabolised to lactate

Question 13

what is induced fit?

Answer 13

binding of glucose to hexokinase induces a large conformational change
happens in the activation site
it prevents catalysis of ATP hydrolysis

Question 14

what is the role of the blood stream in exercise?

Answer 14

to transport chemicals form one cell to another

Question 15

what do metabolic reactions in the muscles do when exercising

Answer 15

destroy the delicate balance of gases and nutrients in the body

Question 16

what does the blood deliver … whilst doing what?

Answer 16

the blood delivers oxygen (bound to haemoglobin) to the muscle cell while removing the waste products CO2 (as carbonate) and lactic acid (as lactate)

Question 17

describe the process known as glycogenesis

Answer 17

the liver can decease the concentration of glucose in the blood by converting excess glucose –> glycogen
this process can be reversed with increasing the concentration

Question 18

where is glycogen found?

Answer 18

large polysaccharide found in the liver and muscle cells

Question 19

what does the lungs restore
what does the liver restore

Answer 19

balance of gases
balance of nutrients

Question 20

how can the liver decrease the acidity of the blood?
what is this process called?

Answer 20

by converting lactate to glucose
gluconeogenesis