Table of contents

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m

1. Introduction to Biochemistry

Proteins

Biochemistry

1. Introduction to Biochemistry

Proteins

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Multiple Choice

Which of the following statements about protein absorption and transport is FALSE?

After absorption, amino acids enter the portal circulation and are transported to the liver.

Amino acids are absorbed primarily in the small intestine via active transport mechanisms.

Dipeptides and tripeptides can be absorbed by enterocytes and are further hydrolyzed inside the cell.

Intact dietary proteins are commonly absorbed into the bloodstream without prior digestion.

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Verified step by step guidance

Step 1: Understand the process of protein digestion and absorption. Proteins are broken down into smaller units (amino acids, dipeptides, and tripeptides) during digestion. This occurs primarily in the stomach and small intestine through the action of enzymes like pepsin and pancreatic proteases.

Step 2: Learn how amino acids, dipeptides, and tripeptides are absorbed. Amino acids are absorbed in the small intestine via active transport mechanisms, which require energy. Dipeptides and tripeptides can also be absorbed by enterocytes (intestinal cells) and are hydrolyzed into amino acids within the cell.

Step 3: Explore the transport of absorbed amino acids. After absorption, amino acids enter the portal circulation (blood vessels leading to the liver) and are transported to the liver for further metabolism or distribution to other tissues.

Step 4: Evaluate the statement about intact dietary proteins. Intact dietary proteins are not commonly absorbed into the bloodstream without prior digestion. Proteins must be broken down into smaller units before absorption, as the body cannot directly utilize intact proteins.

Step 5: Identify the false statement. Based on the understanding of protein digestion and absorption, the false statement is: 'Intact dietary proteins are commonly absorbed into the bloodstream without prior digestion.' This contradicts the established process of protein digestion and absorption.