bio digestion multiple choice

Question 1

What is a tissue?

A) A group of cells that work together to perform a specific function
B) An individual cell with a unique function
C) A layer of skin in the body
D) A complete organ in the body

Answer 1

Answer: A) A group of cells that work together to perform a specific function

Question 2

Which of the following is an organ in the human digestive system?

A) Mitochondria
B) Stomach
C) Muscles
D) Alveoli

Answer 2

B) Stomach

Question 3

Which organ absorbs nutrients from digested food?

A) Stomach
B) Liver
C) Small intestine
D) Large intestine

Answer 3

Answer: C) Small intestine

Question 4

What is the main role of the large intestine?

A) To absorb nutrients
B) To digest proteins
C) To store bile
D) To absorb water from undigested food

Answer 4

D) To absorb water from undigested food

Question 5

What nutrient does the Biuret test identify in food?

A) Carbohydrates
B) Protein
C) Lipids
D) Starch

Answer 5

Answer: B) Protein

Question 6

What color change occurs in a positive iodine test for starch?

A) Red to blue
B) Blue to purple
C) Brown to blue-black
D) Clear to white

Answer 6

C) Brown to blue-black

Question 7

Which nutrient is primarily used for energy in the human body?

A) Carbohydrates
B) Proteins
C) Lipids
D) Vitamins

Answer 7

Answer: A) Carbohydrates

Question 8

Which test would you use to detect lipids in a food sample?

A) Biuret test
B) Emulsion test
C) Benedict’s test
D) Iodine test

Answer 8

Answer: B) Emulsion test

Question 9

What are enzymes?

A) Types of sugars
B) Proteins that act as biological catalysts
C) Structures within cells that provide energy
D) Hormones that regulate growth

Answer 9

Answer: B) Proteins that act as biological catalysts

Question 10

Which enzyme breaks down starch?

A) Protease
B) Lipase
C) Amylase
D) Catalase

Answer 10

Answer: C) Amylase

Question 11

The ‘lock and key’ model is used to describe:
A) How nutrients are absorbed in the stomach
B) The process of emulsification
C) The way enzymes interact with specific substrates
D) The formation of cell membranes

Answer 11

Answer: C) The way enzymes interact with specific substrates

Question 12

What is the active site of an enzyme?
A) The part that binds to substrates
B) The cell in which the enzyme is found
C) The section that determines the enzyme’s color
D) The part that digests the enzyme itself

Answer 12

Answer: A) The part that binds to substrates

Question 13

Which factor can denature an enzyme?
A) Low temperature
B) High pH or extreme temperatures
C) Neutral pH
D) Stable conditions

Answer 13

B) High pH or extreme temperatures

Question 14

What is the optimal pH for pepsin, an enzyme in the stomach?
A) Neutral (pH 7)
B) Highly acidic (around pH 2)
C) Slightly basic (pH 8)
D) Neutral to slightly acidic (pH 6)

Answer 14

Answer: B) Highly acidic (around pH 2)

Question 15

What happens to enzyme activity as temperature increases to its optimal point?
A) It decreases
B) It remains unchanged
C) It increases
D) It stops completely

Answer 15

Answer: C) It increases

Question 16

Which factor will increase enzyme activity until all active sites are occupied?
A) Substrate concentration
B) Water availability
C) Light intensity
D) Size of substrate

Answer 16

A) Substrate concentration

Question 17

What is the role of saliva in digestion?
A) To neutralize stomach acid
B) To moisten food and begin breaking down starch
C) To store bile
D) To digest proteins

Answer 17

B) To moisten food and begin breaking down starch

Question 18

Which organ produces bile?
A) Stomach
B) Gallbladder
C) Liver
D) Pancreas

Answer 18

Answer: C) Liver

Question 19

What is peristalsis?
A) The release of bile into the stomach
B) The breaking down of proteins into amino acids
C) Wave-like muscle contractions that move food through the digestive tract
D) The process of nutrients being absorbed in the large intestine

Answer 19

C) Wave-like muscle contractions that move food through the digestive tract

Question 20

How does bile aid in the digestion of fats?
A) By breaking down proteins
B) By emulsifying fats for easier digestion
C) By neutralizing stomach acid
D) By storing nutrients

Answer 20

B) By emulsifying fats for easier digestion

Question 21

What is the function of the pancreas in the digestive system?
A) To store bile
B) To produce digestive enzymes like amylase, lipase, and protease
C) To absorb nutrients
D) To remove waste from the blood

Answer 21

B) To produce digestive enzymes like amylase, lipase, and protease

Question 22

What type of enzyme breaks down proteins into amino acids?
A) Amylase
B) Protease
C) Lipase
D) Catalase

Answer 22

Answer: B) Protease

Question 23

Which nutrient provides the body with insulation and long-term energy storage?
A) Carbohydrates
B) Proteins
C) Lipids (fats)
D) Vitamins

Answer 23

Answer: C) Lipids (fats)

Question 24

What is the primary function of villi in the small intestine?
A) To increase surface area for nutrient absorption
B) To secrete enzymes for digestion
C) To mix food with bile
D) To break down large food molecules

Answer 24

Answer: A) To increase surface area for nutrient absorption

Question 25

What is the role of hydrochloric acid in the stomach?
A) To digest fats
B) To neutralize bile
C) To provide an acidic environment for enzymes to function
D) To absorb nutrients

Answer 25

C) To provide an acidic environment for enzymes to function

Question 26

Which of the following is a reason why antibiotics do not work against viruses?
A) Viruses lack the cell structures antibiotics target
B) Viruses are resistant to all drugs
C) Viruses cannot be killed by any treatment
D) Antibiotics can only kill fungi

Answer 26

A) Viruses lack the cell structures antibiotics target

Question 27

What is the process of emulsification in digestion?
A) Breaking down proteins
B) Mixing nutrients with blood
C) Breaking down large fat droplets into smaller ones
D) Filtering waste products from blood

Answer 27

C) Breaking down large fat droplets into smaller ones

Question 28

What is the purpose of mucus in the digestive system?
A) To digest carbohydrates
B) To neutralize acids
C) To protect the lining of the digestive tract
D) To break down proteins

Answer 28

C) To protect the lining of the digestive tract

Question 29

Where does most chemical digestion and nutrient absorption occur?
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine

Answer 29

C) Small intestine

Question 30

What does the Benedict’s test identify in a food sample?
A) Starch
B) Lipids
C) Sugars
D) Proteins

Answer 30

C) Sugars

Question 31

Which part of the digestive system is primarily responsible for water absorption?
A) Small intestine
B) Large intestine
C) Stomach
D) Pancreas

Answer 31

B) Large intestine

Question 32

Which enzyme is responsible for breaking down fats into fatty acids and glycerol?
A) Amylase
B) Protease
C) Lipase
D) Pepsin

Answer 32

Answer: C) Lipase

Question 33

In which part of the digestive system does the absorption of most vitamins and minerals occur?
A) Mouth
B) Large intestine
C) Small intestine
D) Stomach

Answer 33

C) Small intestine

Question 34

What is the role of the esophagus in digestion?
A) To produce bile
B) To absorb nutrients
C) To transport food from the mouth to the stomach
D) To break down proteins

Answer 34

C) To transport food from the mouth to the stomach

Question 35

Which of the following increases the surface area in the small intestine for nutrient absorption?
A) Bile
B) Enzymes
C) Villi
D) Gastric acid

Answer 35

Answer: C) Villi

Question 36

What does pepsin specifically break down?
A) Carbohydrates
B) Proteins
C) Fats
D) Fiber

Answer 36

B) Proteins

Question 37

Where is bile stored before it is released into the small intestine?
A) Stomach
B) Gallbladder
C) Pancreas
D) Liver

Answer 37

B) Gallbladder

Question 38

Which of the following is NOT a function of the liver?
A) Producing bile
B) Filtering toxins from the blood
C) Producing insulin
D) Storing glucose as glycogen

Answer 38

C) Producing insulin

Question 39

What happens to enzymes when they are exposed to extremely high temperatures?
A) They work faster
B) They break down substrates more efficiently
C) They denature and lose their function
D) They increase in size

Answer 39

C) They denature and lose their function

Question 40

Which component of food is broken down into glucose molecules for energy?
A) Proteins
B) Fats
C) Carbohydrates
D) Nucleic acids

Answer 40

C) Carbohydrates

Question 41

How does the structure of villi in the small intestine maximize nutrient absorption?
A) Villi are large, finger-like projections that slow down food movement.
B) Villi have microvilli on their surface to increase surface area further.
C) Villi are smooth to allow quick passage of food through the intestine.
D) Villi contain digestive enzymes that actively transport nutrients.

Answer 41

B) Villi have microvilli on their surface to increase surface area further.

Question 42

What is the effect of a high pH on pepsin, an enzyme active in the stomach?
A) Pepsin becomes more efficient at breaking down proteins.
B) Pepsin is denatured and loses its function.
C) Pepsin changes shape but remains effective.
D) Pepsin is unaffected by changes in pH.

Answer 42

Answer: B) Pepsin is denatured and loses its function.

Question 43

Which of the following statements best explains why enzymes are specific to certain reactions?
A) Enzymes only function in the stomach.
B) Enzymes are designed to have multiple active sites for different substrates.
C) Each enzyme has an active site that only fits certain substrate molecules.
D) Enzymes function best in low temperatures and only interact with a few molecules.

Answer 43

C) Each enzyme has an active site that only fits certain substrate molecules.

Question 44

Why is bile important in the digestion of fats, even though it is not an enzyme?
A) Bile breaks down fat molecules chemically.
B) Bile increases stomach acid to digest fat.
C) Bile emulsifies fats, increasing the surface area for enzyme action.
D) Bile transports fats to the liver for digestion.

Answer 44

C) Bile emulsifies fats, increasing the surface area for enzyme action

Question 45

Which of the following best explains why enzymes have an optimum temperature?
A) Enzymes function better at high temperatures.
B) Too low a temperature denatures the enzyme.
C) Optimum temperature ensures the highest rate of reaction without denaturation.
D) The active site only forms at a specific temperature.

Answer 45

C) Optimum temperature ensures the highest rate of reaction without denaturation.

Question 46

What is the primary reason why starch digestion begins in the mouth and not in the stomach?
A) Starch can only be digested by stomach acid.
B) The enzyme amylase, which breaks down starch, is present in saliva.
C) The stomach has no enzymes for breaking down carbohydrates.
D) Amylase only becomes active at acidic pH levels.

Answer 46

B) The enzyme amylase, which breaks down starch, is present in saliva.

Question 47

Which of the following does NOT happen during the process of emulsification?
A) Large fat droplets are broken into smaller droplets.
B) Bile salts surround fat molecules to keep them separate.
C) Fat molecules are chemically broken down into fatty acids and glycerol.
D) Emulsified fats increase enzyme efficiency for digestion.

Answer 47

C) Fat molecules are chemically broken down into fatty acids and glycerol

Question 48

What would likely happen to enzyme activity if the enzyme concentration were increased but substrate concentration remained constant?
A) The rate of reaction would continue to increase.
B) The rate of reaction would remain unchanged once all substrates are bound.
C) Enzyme activity would decrease as more enzymes compete for substrates.
D) Substrate concentration would increase to match enzyme activity.

Answer 48

B) The rate of reaction would remain unchanged once all substrates are bound.

Question 49

Which statement best describes why proteins are not absorbed directly into the bloodstream in the digestive system?
A) Proteins are too small to be detected by blood vessels.
B) Proteins need to be digested into amino acids to pass through the intestinal wall.
C) Proteins are absorbed by the liver and then broken down.
D) Proteins dissolve in the stomach and are lost as waste.

Answer 49

B) Proteins need to be digested into amino acids to pass through the intestinal wall

Question 50

How does temperature influence the shape of an enzyme’s active site?
A) Temperature does not affect the enzyme’s shape.
B) Lower temperatures cause the active site to expand.
C) Higher temperatures may denature the enzyme, altering the active site.
D) Enzyme shape only changes due to pH, not temperature.

Answer 50

C) Higher temperatures may denature the enzyme, altering the active site.