Respiration

Question 1

Why do living organisms need to respire?

Answer 1

Respiration releases energy stored which synthesises molecules of ATP. This provides energy to drive biological processes

Question 2

what processes does ATP drive?

Answer 2

active transport, endocytosis, DNA replication, movement and activation of chemicals

Question 3

What is the role of ATP?

Answer 3

intermediary between energy releasing and energy consuming metabolic reactions

Question 4

what is the immediate energy source for a metabolic reaction?

Answer 4

ATP

Question 5

what is glycolysis?

Answer 5

the first stage of respiration which converts glucose to pyruvate

Question 6

What are the three main stages of glycolysis?

Answer 6

1. Phosphorylation of glucose to hexose bisphosphate
2. Splitting each hexose bisphosphate into two triose phosphate molecules
3. Oxidation of triose phosphate

Question 7

what type of reactions need co enzymes that accept the hydrogen atoms?

Answer 7

oxidation and reduction reactions

Question 8

What is NAD?

Answer 8

(nicotinamide adenine dinucleotide) a non protein molecule that helps dehydrogenase enzymes to carry out oxidation reactions by accepting 2 hydrogen atoms

Question 9

what does reduced NAD do?

Answer 9

carries the protons and electrons to the cristae of mitochondria for oxidative phosphorylation

Question 10

what happens to rNAD when it delivers the protons and electrons?

Answer 10

becomes oxidised and can be reused

Question 11

what happens during phosphorylation?

Answer 11

1. one molecule of ATP is hydrolysed and the released phosphoryl group is added to glucose to make hexose monophosphate
2. Another ATP is hydrolysed and the phosphoryl group adds to the hexose phosphate and forms hexose bisphosphate (the sugar has a phosphate group at c1 and c6)

Question 12

what happens when the hexose bisphosphate is split?

Answer 12

each molecule is split into two three-carbon molecules, triose phosphate, each with a phosphate group attached

Question 13

what happens during the oxidation of triose phosphate to pyruvate?

Answer 13

1. Dehydrogenase enzymes, aided by coenzyme NAD, remove hydrogens from triose phosphate
2. The two molecules of NAD accept the hydrogen atoms and become reduced
3. Two molecules of NAD are reduced for every molecule of glucose undergoing this process

Question 14

What are the net products of glycolysis?

Answer 14

x2 ATP
x2 rNAD
x2 pyruvate