Ib Biology 12 Hl

1. Explain why digestion of large food molecules is essential [3].

Digesting large food molecules helps in weight loss.

Large food molecules are more nutritious than smaller molecules.

Absorption of large food molecules directly into the blood stream is more efficient.

Food molecules are polymers and insoluble. Food molecules must be digested from insoluble to smaller soluble molecules before being absorbed in the blood stream.Polymers are large food molecules that when digested become monomers

The digestion of large food molecules is essential to break them down into smaller, soluble molecules that can be absorbed in the blood stream. This process allows the body to utilize the nutrients efficiently.

Explanation

The digestion of large food molecules is essential to break them down into smaller, soluble molecules that can be absorbed in the blood stream. This process allows the body to utilize the nutrients efficiently.

2. Compare the products, source, substrates, pH condition, and action of one amylase, one protease, and one lipase.

Amylase: salivary amylasesource: mouthsubstrate: amylose (starch)product: disaccharide maltosepH: 7.5-7.8 (basic)action: hydrolysis of 1-4 glycotic bonds Protease: pepsinsource: stomachsubstrate: polypeptidesproduct: smaller peptidespH: 2 (very acidic)action: endopeptidase Lipase: pancreatic lipasesource: pancreassubstrate: triglyeride lipidsproduct: fatty acid chains and glycerolspH: 7.2 (basic)action: hydrolysis of lipids into fatty acids and glycerol molecules

The correct answers provide accurate information about the sources, substrates, pH conditions, and actions of amylase, protease, and lipase. The incorrect answers contain misinformation about these enzymes, highlighting the importance of understanding their specific characteristics in digestion.

Explanation

The correct answers provide accurate information about the sources, substrates, pH conditions, and actions of amylase, protease, and lipase. The incorrect answers contain misinformation about these enzymes, highlighting the importance of understanding their specific characteristics in digestion.

3. Define endopeptidase.

A type of carbohydrate found in plants.

A process involving the synthesis of nucleic acids.

The breakdown of lipids into fatty acids and glycerol.

The hydrolysis of polypeptides into peptides (polymer to monomer) using enzymes

Endopeptidase specifically refers to the hydrolysis of polypeptides into peptides using enzymes, and it is not related to carbohydrates, nucleic acids, or lipids.

Explanation

Endopeptidase specifically refers to the hydrolysis of polypeptides into peptides using enzymes, and it is not related to carbohydrates, nucleic acids, or lipids.

4. The action of pancreatic lipases require the presence of what that emulsify lipids?

Bile salts

Amylase

Glucagon

Insulin

Pancreatic lipases specifically require bile salts to emulsify lipids for digestion. Insulin and glucagon are hormones involved in glucose regulation, while amylase is an enzyme that aids in the digestion of carbohydrates.

Explanation

Pancreatic lipases specifically require bile salts to emulsify lipids for digestion. Insulin and glucagon are hormones involved in glucose regulation, while amylase is an enzyme that aids in the digestion of carbohydrates.

5. What are the effects of emulsification?

1. inhibits the breakdown of fats2. reduces the efficiency of digestive enzymes3. causes the separation of lipids from water

1. increases the surface area of lipids for the digestion of fats2. exposes the glycerol "head" structure to the enzyme

Emulsification actually helps in the digestion of fats by increasing surface area and exposing the glycerol 'head' structure to enzymes. The incorrect answers provided are not aligned with the positive effects of emulsification.

Explanation

Emulsification actually helps in the digestion of fats by increasing surface area and exposing the glycerol 'head' structure to enzymes. The incorrect answers provided are not aligned with the positive effects of emulsification.

6. Draw and label a diagram of the digestive system.

A diagram of the circulatory system.

See diagram

A diagram of the respiratory system.

A diagram of the nervous system.

The correct answer should focus on the digestive system, which includes organs such as the mouth, esophagus, stomach, small intestine, large intestine, liver, and pancreas. Incorrect answers refer to other body systems unrelated to digestion.

Explanation

The correct answer should focus on the digestive system, which includes organs such as the mouth, esophagus, stomach, small intestine, large intestine, liver, and pancreas. Incorrect answers refer to other body systems unrelated to digestion.

7. Define digestion.

Breaking down food into smaller particles

The conversion of food into energy

The hydrolysis of polymers to monomers

The process of absorbing nutrients from food

Digestion specifically refers to the process of breaking down large molecules into smaller molecules that can be absorbed by the body.

Explanation

Digestion specifically refers to the process of breaking down large molecules into smaller molecules that can be absorbed by the body.

8. Outline the function of the stomach.

(a) Absorbs nutrients from food

Responsible for storing food from meal and beginning protein digestion (a) Lumen of the stomach stores the food from a meal (b) Gastric pits from which mucus, enzymes and acid are secreted (c) Mucus secreting cells. Mucus protects the surface of the stomach from auto-digestion (d) Parietal cells that produce HCL which kills microorganism that enter the digestive system (food & tracheal mucus). This also converts inactive pepsinogen to active pepsin (e) Chief cells: produces pepsinogen a protease enzyme

(b) Regulates blood sugar levels

(c) Aids in oxygen transport in the body

The correct function of the stomach is actually to store food from a meal and begin protein digestion. It does not absorb nutrients directly, regulate blood sugar levels, or aid in oxygen transport.

Explanation

The correct function of the stomach is actually to store food from a meal and begin protein digestion. It does not absorb nutrients directly, regulate blood sugar levels, or aid in oxygen transport.

9. Outline the function of the small intestine.

(a) Villus which increase the surface area for absorption of the products of digestion

(c) Lacteals are connect to the lymphatic system for the transport of lipids.

Responsible for completing digestion and absorbing products of digestion (a) Villus which increase the surface area for absorption of the products of digestion(b) Microvilli border of the epithelial cell increases the surface are for absorption. (c) Lacteals are connect to the lymphatic system for the transport of lipids.(d) In the wall of the small intestine are the blood vessels to transport absorbed products to the general circulation, There are also the muscle to maintain peristalsis

(b) Microvilli border of the epithelial cell increases the surface area for absorption.

The small intestine is a vital organ in the digestive system responsible for completing the digestion process and absorbing the products of digestion. It achieves this through various structures and mechanisms such as the villi, microvilli, lacteals for lipid transport, blood vessels for product transportation, and muscle for peristalsis.

Explanation

The small intestine is a vital organ in the digestive system responsible for completing the digestion process and absorbing the products of digestion. It achieves this through various structures and mechanisms such as the villi, microvilli, lacteals for lipid transport, blood vessels for product transportation, and muscle for peristalsis.

10. Distinguish between absorption and assimilation.

Absorption is the process of converting soluble products into insoluble ones for energy production directly in tissues, while assimilation involves the direct uptake of insoluble food molecules by tissues for digestion.

Absorption involves transporting insoluble food molecules directly to tissues for use, while assimilation involves soluble products being excreted as waste.

Absorption refers to the breakdown of soluble products into insoluble molecules for storage, while assimilation involves the circulation of these molecules in the bloodstream.

Insoluble food molecules are digested to soluble products in the lumen of the gut. Absorption:The soluble products are first taken up by various mechanisms into the epithelial cells that line the gut. These epithelial cells then load the various absorbed molecules into the blood stream. Assimilation:The soluble products of digestion are then transported to the various tissues by the circulatory system. The cells of the tissues then absorb the molecules for use within this tissues

Absorption and assimilation are key processes in the digestive system where absorption refers to the uptake of soluble products into the bloodstream from the gut lining, whereas assimilation involves the utilization of these absorbed molecules by tissues for energy and growth.

Explanation

Absorption and assimilation are key processes in the digestive system where absorption refers to the uptake of soluble products into the bloodstream from the gut lining, whereas assimilation involves the utilization of these absorbed molecules by tissues for energy and growth.