Lipids 3

Question 1

Where can fatty acids be found?

Answer 1

In our diet (essential fatty acids) and from the synthesis of excess carbohydrates and protein components.

Question 2

Where are the 3 places fatty acid synthesis occurs?

Answer 2

Liver
Lactating mammary gland
Adipose tissue

In the cytosol of all.

Question 3

Where is acetyl CoA formed?

Answer 3

In the mitochondria so needs transported to the cytosol.

Question 4

What part of acetyl CoA can not pass through the mitochondrial membrane?

Answer 4

CoA

Question 5

What binds with acetyl CoA to allow it to pass through the mitochondrial membrane and what enzyme is used?

Answer 5

Oxaloacetate to make citrate. Citrate synthase.

Question 6

What enzyme is used in the following reactions:

Oxaloacetate -> Malate
Malate -> Pyruvate
Pyruvate -> Oxaloacetate

Answer 6

Malate dehydrogenase
Malate Enzyme
Pyruvate Carboxylase

Question 7

What is acetyl CoA carboxylase and what is its function?

Answer 7

Key regulatory enzyme which is activated by citrate signalling there is enough glucose.

Question 8

What deactivates acetyl CoA carboxylase?

Answer 8

Palmitoyl CoA (enough fatty acid has been made).
Glucagon/epinephrine.

Question 9

What is the overall reaction for palmitate?

Answer 9

8 Acetyl CoA + 14 NADPH + 14 H+ + 7 ATP -> Palmitate + 8 CoA + 14 NADP+ + 7 ADP + 7 Pi + 7 H2O

Question 10

How many times is the elongation cycle repeated?

Answer 10

6 using Malonyl CoA to produce Palmityl ACP.

Question 11

The intermediates in fatty acid synthesis are ______ linked to the acyl carrier protein.

Answer 11

Covalently

Question 12

Any further modifications of palmitate or dietary fatty acids occurs in the ______ and the ______ by diverse enzymes.

Answer 12

Mitochondria, endoplasmic reticulum.

Question 13

What is the process of fatty acid synthesis?

Answer 13

Acetyl CoA -> Fatty Acid -> Triacylglycerol -> VLDL -> Adipose tissue

Question 14

Define steroid hormone.

Answer 14

Chemical substances that serve as chemical messengers.

Question 15

Define cholesterol.

Answer 15

Starting material for the synthesis of steroid hormones.

Question 16

Define eicosanoids.

Answer 16

Are derived from a 20-carbon unsaturated fatty acid and are synthesised around the body.

Question 17

What is the function of sterols such as cholesterol?

Answer 17

Component of cell membrane
Precursor to other substances
Synthesis is mainly in the liver and only found in animal foods

Question 18

Define statins.

Answer 18

Inhibit HMG-CoA reductase that is essential in cholesterol synthesis.

Question 19

Give the 6 thing eicosanoids regulate.

Answer 19

Inflammatory response
Pain and fever
Blood pressure
Blood clotting induction
Many reproductive functions and menstrual cramps
Sleep/Wake cycle

Question 20

Define Cox inhibitors.

Answer 20

Anti-inflammatory and fever reducing property of aspirin due to inhibition of Cox 1 enzyme and prostaglandin synthesis.

Question 21

What is the function of aspirin?

Answer 21

Inhibits thromboxanes that cause clotting.