BIOCHEM LEC - Lipid Metabolism

Cytosol

Where does fatty acids synthesis occur?

Acetyl-CoA Carboxylase (ACC)

What is the conversion of acetyl-CoA to malonyl-CoA catalyzed by?

Triglycerides

What happens to fatty acids when they are synthesized?

They are esterified into phospholipids and _____.

Fed State

When is fatty acid synthesis stimulated?

During the _____ by insulin.

Ribulose-5-phosphate

The final product of the oxidative phase of the pentose phosphate pathway (PPP).

NADPH

What do steps 1 and 3 of the oxidative phase produce?

Lipid Biosynthesis

How is NADPH different from NADH?

NADPH is used in _____ _____.

Phospholipids and triglycerides

What can acetyl-CoA become?

98%

What percentage of dietary lipids are triglycerides (TAGs)?

None

What effect do salivary enzymes have on lipids?

Chyme

What happens to TAGs in the stomach?

They change to small globules called _____.

10%

What percentage of TAGs are hydrolyzed by gastric lipases?

They make you feel full longer.

Why do high-fat foods stay in the stomach longer?

Micelles

What is the role of bile acids in digestion?

They convert TAGs into _____.

Fasted; Glucagon

What triggers the breakdown of fats?

The _____ state with _____ release.

Hormone-sensitive lipase (HSL)

What enzyme initiates the hydrolysis of triglycerides?

Absorbed by the cell

What happens to fatty acids and glycerol in the bloodstream?

Adipocytes

Where are TAGs primarily stored in the body?

Insulation and Protection against shock

What is the function of adipose tissue?

Beta-oxidation

What is another name for fatty acid oxidation?

By 2 carbons at a time into Acetyl-CoA

How are fatty acids broken down in beta-oxidation (fatty acid oxidation)?

Mitochondrial Matrix

Where does fatty acid oxidation (beta oxidation) occur?

Transport Proteins

What is required for the transport of fatty acids to the mitochondrial matrix?

4

How many total steps are there in fatty acid oxidation (beta oxidation)?

Steps in Fatty Acid Oxidation (Beta Oxidation)

1. Dehydrogenation

2. Hydration

3. Second dehydrogenation

4. Thiolysis

By considering ATP produced per round

How is ATP production calculated in fatty acid oxidation (beta oxidation)?

120 ATP Molecules

How many ATP molecules are produced form the oxidation of stearic acid (C18)?

2 ATP Moleculess

How many ATP molecules are needed for the activation of fatty acids?

Acetyl-CoA

What is the building block of the mevalonate pathway?

Fed; Insulin

When is the mevalonate pathway stimulated?

In the _____ state by _____.

Isoprene Unites

What are volatile oils mainly made up of?

Flavors and Fragrances

What are terpenes used for?

Ketogenesis

Production of ketone bodies in mitochondria.

Three Types of Ketone Bodies Produced

1. Acetone

2. Acetoacetate

3. Beta-hydroxybutyrate

Fasting/Starvation

When does ketogenesis occur?

During _____.

Acetyl-CoA overflow from beta-oxidation

What triggers ketogenesis?

Emergency Fuel

Ketone bodies serve as _____ _____ in the brain.

Ketosis

They shift from glucose to ketone body dependence.

Ketonemia

Elevated ketone bodies in the blood.

Ketonuria

Elevated ketone bodies in the urine.

Ketoacidosis

Elevated ketone bodies causing acidosis.

It induces ketosis

What is the ketogenic diet’s effect in ketosis?

Diabetic Ketoacidosis

Condition from insufficient insulin leading to ketone production.

Decreases

What happens to insulin levels in diabetic ketoacidosis?

Increases

What happens to glucagon levels in diabetic ketoacidosis?

Increases

What happens to lipolysis, beta-oxidation, and ketogenesis in diabetic ketoacidosis?