Lecture 13. Krebs Cycle

Question 1

What tissue has the function of maintenance of reduced glutathione ?

Answer 1

Red blood cells

Question 2

What tissue has the function of fatty acid and cholesterol synthesis ?

Answer 2

Liver

Question 3

What tissues have a function of fatty acid synthesis ?

Answer 3

1. Liver
2. Adipose tissue
3. Mammary gland

Question 4

What tissues have a function of steroid synthesis ?

Answer 4

1. Adrenal gland
2. Testes
3. Ovary

Question 5

What is glucose-6-phosphate dehydrogenase ?

Answer 5

An x-linked recessive genetic condition that predisposes to haemolysis (spontaneous destruction of red blood cells) and resultant jaundice in response to a number of triggers

Question 6

What does the reduced form of glutathione do ?

Answer 6

Mop up free radicals

Question 7

What does the reduction of oxidised glutathione require ?

Answer 7

NADPH2

Question 8

What detoxifying pathway require NADPH

Answer 8

1. Reduction of oxidised glutathione

2. Cytochrome P450 monooxygenases

Question 9

What synthesising pathways require NADPH

Answer 9

1. Fatty acid biosynthesis
2. Cholesterol biosynthesis
3. Neurotransmitter biosynthesis
4. Nucleotide biosynthesis

Question 10

How are pentose phosphate pathway and glycolysis linked ?

Answer 10

1. Transketolase

2. Transaldose

Question 11

Where does the pentose phosphate pathway occur ?

Answer 11

Occurs in all cells but particularly active in antioxidant or cells which make hormones

Question 12

What is the pentose phosphate pathway a source of ?

Answer 12

1. NADPH2
2. Ribose (5c) sugars
3. Interconverts sugar with glycolytic/gluconeogenic pathway

Question 13

What is the pentose phosphate pathway also known as ?

Answer 13

Hexose monophosphate shunt

Question 14

What is the link between oxaloacetate and other pathways ?

Answer 14

Forms other amino acids, purines and pyrimidines

Question 15

What is the link between succinyl CoA and other pathways ?

Answer 15

Forms porphyrins, heme and chlorophyll

Question 16

What is the link between alpha-ketoglutarate and other pathways ?

Answer 16

Forms glutamate which is a transaminator and from there forms other amino acids then purines

Question 17

What is the link between citrate and other pathways ?

Answer 17

Forms fatty acids and sterols by using a tricarboxylic acid transporter

Question 18

What is pyruvate dehydrogenase a link between ?

Answer 18

carbohydrate and lipid/fatty acid metabolism

Question 19

Can fatty acids be converted to glucose ?

Answer 19

No

Question 20

What is acetyl CoA a precursor of ?

Answer 20

The synthesis of fatty acids and cholesterol

Question 21

What is citrate synthase used for ?

Answer 21

Marker of mitochondrial abundance in muscle biopsies

Question 22

Why does the body preferentially burn fat over sugar ?

Answer 22

Acetyl CoA

Question 23

What decreases pyruvate dehydrogenase activity ?

Answer 23

A high acetyl CoA/CoA ratio and a high NADH2/NAD+

Question 24

Where does krebs cycle occur ?

Answer 24

Mitochondria

Question 25

What is the pentose phosphate pathway a source of ?

Answer 25

1. NADPH2
2. Ribose (5c) sugars
3. Interconverts sugar with glycolytic/gluconeogenic pathway

Question 26

What is glucose-6-phosphate dehydrogenase ?

Answer 26

An x-linked recessive genetic condition that predisposes to haemolysis (spontaneous destruction of red blood cells) and resultant jaundice in response to a number of triggers