Carbohydrates and Their Metabolism

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What are the products of pyruvate oxidation?

2 acetyl CoA, 2 NADH, 2 CO2 (correct)

2 acetyl CoA, 4 NADH, 2 CO2

2 ATP, 6 NADH, 2 FADH2, 4 CO2

4 acetyl CoA, 4 NADH, 2 CO2

The citric acid cycle directly consumes oxygen.

False

What is the role of amylases in carbohydrate digestion?

Convert polysaccharides to monosaccharides

Convert disaccharides to polysaccharides

Convert polysaccharides to disaccharides (correct)

Convert monosaccharides to polysaccharides

Where does gluconeogenesis primarily occur?

Liver Signup and view all the answers

The major substrates for gluconeogenesis include lactate, pyruvate, and ________ acids.

glucogenic Signup and view all the answers

Gluconeogenesis is involved in the catabolism of carbohydrates.

False Signup and view all the answers

Match the following enzyme processes with their main effects:

Pyruvate oxidation = Produces acetyl CoA Citric acid cycle = Generates ATP and electron carriers Gluconeogenesis = Synthesizes glucose Electron transport chain = Produces ATP from high-energy electrons Signup and view all the answers

Name the process by which glucose is converted into acetyl CoA.

Oxidative decarboxylation Signup and view all the answers

The primary energy source for most body tissues is ____.

glucose Signup and view all the answers

What happens to NADH and FADH2 produced during the citric acid cycle?

Sent to the ETC for ATP production Signup and view all the answers

The citric acid cycle turns twice for every starting glucose.

True Signup and view all the answers

Match the biochemical processes with their corresponding type:

Glycolysis = Catabolism Glycogenesis = Anabolism Krebs cycle = Catabolism Gluconeogenesis = Anabolism Signup and view all the answers

What compound does acetyl CoA combine with to initiate the citric acid cycle?

Oxaloacetate Signup and view all the answers

What products are generated from one molecule of glucose during glycolysis?

2 ATP, 2 pyruvate, and 2 NADH Signup and view all the answers

Glycogen is stored primarily in the liver after glucose absorption.

True Signup and view all the answers

What are the two types of enzymes important for carbohydrate digestion?

Amylases and disaccharidases Signup and view all the answers

Study Notes

Carbohydrates

Carbohydrates are a significant class of biomolecules
They are condensation products of more than 10 monosaccharide units
These units can link linearly (α(1-4) linkage) or branched (α(1-6) linkage)
Common examples include starch, glycogen, cellulose, dextran, inulin and chitin.

Digestion of Carbohydrates

Digestion relies on two types of enzymes:
- Amylases break down polysaccharides into disaccharides
- Disaccharidases break down disaccharides into monosaccharides
Examples of disaccharidases include:
- Maltase breaks down maltose
- Sucrase breaks down sucrose
- Lactase breaks down lactose

Carbohydrate Metabolism

Carbohydrate catabolism involves:
- Glycolysis
- Krebs cycle
- Pentose phosphate pathway
- Glycogenolysis
Carbohydrate anabolism includes:
- Gluconeogenesis
- Glycogenesis

Glycolysis

Glycolysis is the breakdown of glucose in the cytoplasm of all cells in the body
- It may be aerobic (in the presence of oxygen) or anaerobic (in the absence of oxygen)
  - Aerobic glycolysis produces 2 pyruvate and 8 ATP
  - Anaerobic glycolysis produces 2 lactate and 2 ATP
Location: Cytosol
Substrate: Glucose (C₆H₁₂O₆)
Products: 2 pyruvate, 2 ATP, 2 NADH

Pyruvate Oxidation

Location: Mitochondrial matrix
Substrate: 2 pyruvate
Products: 2 acetyl CoA, 2 NADH, 2 CO₂

Krebs Cycle

Also known as the citric acid cycle or tricarboxylic acid cycle
- It takes place in the mitochondrial matrix
- It occurs after pyruvate oxidation
It involves the oxidation of acetyl-CoA to generate ATP, NADH, and FADH₂
Products
- 2 ATP, 6 NADH, 2 FADH₂, 4 CO₂

Gluconeogenesis

It is the formation of glucose from non-carbohydrate sources
- The major substrates include lactate, pyruvate, glucogenic amino acids, propionate and glycerol.
Location: Mainly in the liver, and to a lesser extent in the renal cortex.
The pathway is partly mitochondrial and partly cytoplasmic.
The synthesis of glucose from non-carbohydrate compounds is known as gluconeogenesis.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the fundamental concepts of carbohydrates, including their structure, digestion, and metabolism. It explores the roles of various enzymes in carbohydrate breakdown and the metabolic pathways involved in catabolism and anabolism. Test your understanding of these essential biomolecules!