EduNinja

IB Biology SLB1.2 ProteinsQuestion Bank

B1.2 Proteins

Question 1

[Maximum number: 1]

Edible insects have been a part of traditional human diets in many countries. For example, crickets are insects commonly eaten in Asia and Africa. Many studies have looked at the prospects of raising insects on a commercial scale for direct human consumption as food or indirectly by feeding insects to farm animals.

One factor to consider is which organisms are most efficient at converting the feed they eat into animal protein that can be consumed. A study compared the percentage of mass that was edible in two common farm animals and in crickets.

Question image

Question 1(b)

(a)

The yellow mealworm (Tenebrio molitor) is native to temperate regions of the world and has been studied as a possible means of producing food in countries with that type of climate. The amino acid content of yellow mealworms and cattle was analysed. The table shows the results for seven amino acids that are required in the human diet.

Question image
[ 1 ]

Question 1(b)(i)

(i)

Distinguish between the amino acid contents of yellow mealworms and cattle.

[ 1 ]

Question 1

[Maximum number: 2]

Low protein diets are a widespread problem in the developing world. A low protein diet in a pregnant mother could affect a developing fetus. Other mammals are used as a biomedical model for energy metabolism and malnutrition in humans.

In an experiment to study the effect of protein levels in the diet, pregnant mammals were fed diets with different ratios of protein to carbohydrate:
- low protein : high carbohydrate (LP),
- adequate protein: adequate carbohydrate (AP),
- high protein : low carbohydrate (HP).

The table shows the average birth mass of the offspring and the body mass gain of the mother during the pregnancy. The concentration of several substances in the plasma of the mothers was also recorded. LDL (low density lipoprotein) is considered "bad cholesterol" and HDL (high density lipoprotein) is considered "good cholesterol".

Table

Question 1(d)

(a)

Explain the low birth mass of offspring born to mothers who were fed the LP diet.

[ 2 ]

Question 3

[Maximum number: 1]

Which is an effect of protein denaturation?

A

The order of amino acids is changed when the protein overheats.

B

The bonds between amino acids are broken by condensation.

C

Parts of the protein become linked together by hydrolysis.

D

The three-dimensional structure of the protein is altered.

Question 3

[Maximum number: 1]

How are amino acids joined together to form a dipeptide?

A

Single bond between a carbon and a hydrogen

B

Hydrolysis reaction forming a hydrogen bond

C

Anabolism forming a double bond

D

Condensation reaction forming a peptide bond

Question 4

[Maximum number: 1]

What must vegans ensure when they plan their diet?

A

Higher protein consumption than meat-eaters

B

Sufficient quantities of all essential amino acids are consumed

C

Only proteins with all 20 amino acids are consumed

D

Higher fat consumption than meat-eaters

Question A2

Question A2(a)

Question A2(a)(ii)

(a)
(i)

Define the term non-essential amino acid.

[ 1 ]

Question 2

Question 2(a)

Question 2(a)(i)

(a)
(i)

State how non-essential amino acids can be obtained if they are not present in the diet.

[ 1 ]

Question 7

[Maximum number: 1]

What is a role of sulfur in living organisms?

A

Formation of proteins

B

Formation of carbohydrates

C

Formation of teeth

D

Transmission of nerve impulses

Question 7

[Maximum number: 1]

Which substance in prokaryotes contains sulfur?

A

DNA

B

Phospholipids

C

Proteins

D

Antibiotics

Question A2

Question A2(c)

(a)

Outline the consequences of protein deficiency malnutrition.

[ 2 ]
0 selected