B1 (molecules: carbohydrates & lipids, and proteins)

Question 1

Carbohydrates & Lipids.

Carbohydrates:

Answer 1

Monosaccharides (glucose), disaccharides (sucrose), polysaccharides (starch).

Question 2

Carbohydrates & Lipids.

Lipids:

Answer 2

Triglycerides, phospholipids, steroids.

Question 3

Proteins.

Amino Acid Structure:

Answer 3

Central carbon, amino group, carboxyl group, variable side chain (R-group).

Question 4

Proteins.

Protein Structure:

Answer 4

Primary, secondary, tertiary, quaternary.

Question 5

Proteins.

Enzyme Function:

Answer 5

Catalysts that speed up biochemical reactions.

Question 6

Explain the structural differences between starch and cellulose. How do these differences contribute to their distinct functions in plant cells?

Answer 6

Starch: can be straight or branched and is used as energy storage for plants because it can form compact structures and is easily broken down.

Cellulose: molecules are connected in opposite orientations. Cellulose is found in cell walls and gives plant cells protection and structure.

Question 7

Using a specific enzyme as an example, describe how enzymes facilitate biochemical reactions. Discuss factors that can affect enzyme activity.

Answer 7

Enzymes lower activation energy

Enzyme Example:
Amylase catalyzes starch hydrolysis into maltose in the digestive system.

Factors Affecting Enzyme Activity:

Temperature: Optimal temperature is crucial; high temperatures denature enzymes.
pH Level: Enzymes have an optimal pH range.
Substrate and Enzyme Concentration: Rate increases until saturation.
Cofactors and Coenzymes: Essential for enzyme function.
Inhibitors: Competitive or non-competitive inhibitors can hinder enzyme activity.

Question 8

Explore the structural differences between saturated and unsaturated fats. How do these differences influence the physical properties and health implications of these lipids?

Answer 8

Saturated fats: no double bonds and a straight structure, solid at room temperature.

Unsaturated fats: double bonds, creating kinks, liquid at room temperature.

Saturated fats are associated with cardiovascular risks.

Question 9

Discuss the concept of protein denaturation. Provide examples of factors that can denature proteins and explain the consequences of denaturation on protein function.

Answer 9

Protein denaturation involves the loss of a protein’s three-dimensional structure, disrupting its function.

Factors like temperature, pH changes, and chemicals can denature proteins, affecting enzyme activity and cell functions.

Question 10

Investigate the role of chaperone proteins in protein folding. How do chaperones assist in maintaining proper protein structure?

Answer 10

Chaperone proteins assist in protein folding by preventing misfolding and promoting correct folding.

They play a crucial role in maintaining cellular homeostasis.