Physiology of Metabolism – BIOL1133 Review

Thirty Q&A flashcards covering key metabolic pathways, hormonal control, and clinical correlations from the BIOL1133 Human Anatomy and Physiology II lecture on metabolism.

What is lipolysis and in which tissue does it primarily occur?

The breakdown of triglycerides into glycerol and fatty acids, occurring mainly in adipose tissue.

Define lipogenesis and name two places it can take place.

The synthesis of triglycerides from glycerol and fatty acids; it occurs in adipose tissue and the liver.

Which metabolic pathway converts excess fatty acids into ketone bodies, and where does it occur?

Ketogenesis; it takes place in the liver.

What is ketolysis and which organs rely on it for fuel during fasting?

The breakdown of ketone bodies to generate ATP; relied upon by the heart and neurons.

Describe beta oxidation.

Fatty acids being turned directly into ATP. This is done by the heart

Which pathway breaks one glucose molecule into two pyruvate molecules?

Glycolysis.

Name the overall process that can produce large amounts of ATP in mitochondria.

Cellular respiration

What is glycogenesis and where does it mainly happen?

The formation of glycogen from glucose; it occurs principally in the liver and skeletal muscle.

Define gluconeogenesis and state its primary organ of occurrence.

The synthesis of glucose from non-carbohydrate precursors, primarily taking place in the liver.

Approximately how long can glycogen reserves supply the body with fuel during fasting?

About 1–3 days.

During prolonged fasting (weeks to months), which tissue’s proteins are catabolized for energy?

Skeletal muscle proteins.

Which hormone stimulates glycogenesis?

Insulin.

Which hormone stimulates glycogenolysis and gluconeogenesis?

Glucagon.

What is proteolysis?

The breakdown of proteins into individual amino acids.

Define proteogenesis.

The synthesis of new proteins from amino acids.

What is the primary defect in type 1 diabetes mellitus?

Pancreatic β-cells do not produce insulin.

What characterizes type 2 diabetes mellitus?

Insulin is produced, but body cells show little or no response to it (insulin resistance).

In starvation, which hormone predominates to maintain blood glucose levels?

Glucagon.

Which two types of cells preferentially use ketone bodies during prolonged starvation?

Neurons and cardiac muscle cells (heart).

What is the principal stored form of lipid in adipocytes?

Triglycerides.

Which organ is central to both ketogenesis and gluconeogenesis?

The liver.

What high-energy molecule serves as the cell’s immediate energy currency?

ATP (adenosine triphosphate).

Which hormone stimulates lipolysis in adipose tissue?

Glucagon.

Which hormone promotes lipogenesis?

Insulin.

Which pathway can convert certain amino acids into new glucose during fasting?

Gluconeogenesis.

What is the main role of glycogen stored in skeletal muscle?

To provide glucose for muscle contraction during activity.

Through which pathway is glucose converted to glycogen for storage?

Glycogenesis.

During the early phase of fasting, which fuel source is used first?

Glycogen stores in liver and muscle.

After lipolysis, what happens to the liberated glycerol?

It is transported to the liver, where it can enter glycolysis or be converted to glucose.

What does the breakdown of proteins signify

the final stages of starvation