Biology · Chemistry

Biomolecules and Enzymes

1,501 Questions

This topic focuses on biomolecules, specifically proteins, enzymes, and amino acids. It includes questions on enzyme structures, protein folding, and catalysis. These concepts are crucial for medical and biology competitive exams.

Enzyme catalysisProtein structuresAmino acid synthesisPolypeptide chainsBiomolecule properties

Biomolecules and Enzymes Questions

Multiple choice evs - i constituents of food simple test for nutrients test for nutrients protein and its function nutrients and foodstuffs

Proteins are a polymerisation product of 

  1. Monosaccharides

  2. Muramic acid

  3. Amino acids

  4. All the above.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Amino acids are Linked by peptide bonds to form polypeptide chains. Proteins are linear polymers formed by linking the α-carboxyl group of one amino acid to the α-amino group of another amino acid with a peptide bond (also called an amide bond).

So, the correct answer is option C.

Multiple choice zoology molecular genetics one gene - one enzyme hypothesis component of the cell cell and cell organelles

Today, it is most appropriate to state that a gene controls

  1. one enzyme

  2. one protein

  3. one polypeptide chain

  4. one amino acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

One gene one enzyme hypothesis had many defects so it changed to one gene-one polypeptide.  According to one gene-one polypeptide hypothesis, the information enclosed in one gene is sufficient to form one polypeptide only. Genes control the synthesis of all proteins. Some proteins are enzymes and some are hormones.  Hemoglobin molecule consists of two different polypeptides alpha and beta which are formed by two different genes.

So, the correct option is 'one polypeptide chain'.

Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Absorption of amino acid is dependent upon

  1. Sodium gradient

  2. ATP

  3. Protein gradient

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Amino acids together constitute the proteins. They are absorbed in the blood by active transportation mechanism. They are transported from the lumen into the cells by Na+ amino acid co-transporter using ATP in apical membrane energy by sodium gradient. 
So the correct answer is 'All of the above'.
Multiple choice different stages of growth reproductive system in humans division for growth and reproduction human system biology

Enzyme which becomes more active in aged person is _____________.

  1. Malate dehydrogenase

  2. Aldolase

  3. Lactate dehydrogenase

  4. Acetylcholinestrase
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When ageing is progressing in the human body, different types of oxidising enzymes activity increases because of decreased rate of metabolism.

So, the correct option is ‘Malate dehydrogenase’.

Multiple choice different stages of growth reproductive system in humans division for growth and reproduction human system biology

Protein which plays a significant role in ageing is

  1. Actin

  2. Myosin

  3. Collagen

  4. Elastin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A. Actin - plays an important role in embryogenesis, the healing of wounds and the invasivity of cancer cells.

B. Myosin – plays an important role in muscle contractions and  a variety of movements of nonmuscle cells, including cell division,

C. Collagen – plays a significant role in ageing.

D. Elastin - plays an important role in the biomechanical function of vital body tissues and organs such as the heart, lungs, skin and the vocal folds.

So, the correct option is ‘Collagen’.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

Simple proteins bonded with a non-protein prosthetic group (acting as a cofactor) are called:

  1. Simple proteins

  2. Conjugated proteins

  3. Proteonic proteins

  4. All the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Simple proteins bonded with a non-proteinic prosthetic group (acting as cofactor) are called conjugated proteins.
Examples include  Glycoprotein, Lipoprotein, and Phosphoprotein.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

A holoenzyme contains apoenzyme and ____________ .

  1. isoenzyme

  2. cofactor

  3. inhibitor

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Holoenzyme = Apoenzyme+ Cofactor.

Apoenzyme:-An apoenzyme is an inactive enzyme, activation of the enzyme occurs upon binding of an organic or inorganic cofactor.
Cofactor:-A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme's activity

Multiple choice introduction to mole gas laws and mole concept atoms and molecules chemistry mole concept chemical formula and mole concept

A protein, isolated from a bovine preparation, was subjected to amino acid analysis. The amino acid present in the smallest amount was lysine, $C _6H _{14}N _2O _2$ and the amount of lysine was found to be $365\ mg$ per $100\ g$ protein. What is the minimum molecular mass of the protein?   

  1. $40,000,000$
  2. $40, 000$
  3. $40$
  4. $4, 00,000$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The minimum molecular mass of a protein is calculated based on the assumption that there is at least one molecule or residue of the least abundant component per protein molecule. Since 365 mg (0.365 g) of lysine is present in 100 g of protein, the minimum molecular mass M satisfies (Mass of lysine in 1 mol / M) = (0.365 g / 100 g). Specifically, taking one lysine molecule per protein molecule, M = (Molecular weight of lysine * 100 g) / 0.365 g. The molecular formula of lysine C6H14N2O2 has a molar mass of 146 g/mol. Thus, M = (146 * 100) / 0.365 = 40,000 g/mol.

Multiple choice biology keeping diseases away diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

The most basic amino acid is

  1. Arginine

  2. Hisstidine

  3. Glycine

  4. Glutamine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Glutamine and Glycine are not basic amino acids. Only Arginine and Histidine are basic amino acids. Histidine is weakly charged under physiological ph. Hence, Arginine is the most basic amino acid. 

So the correct option is 'Arginine'.

Multiple choice biology keeping diseases away diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

What part of hemoglobin is affected in sickle cell anaemia?

  1. $\alpha$-polypeptide chains
  2. $\beta$-polypeptide chains
  3. Both $\alpha$- and $\beta$- polypeptide chains

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hemoglobin has four chains: two alpha chains and two beta chains with heme and iron part along with oxygen. There are some hydrophobic substances (water-hating) present on the surface of proteins. These hydrophobic residues forms cluster and pocket-like structure on the surface of beta chains. These pockets are responsible for diseases like sickle cell anemia also in the beta chain the position of glutamic acid at sixth place in the chain is replaced by valine leading to the shape of red blood cells to be sickle-like due to loss of oxygen.

So, the correct option is 'Beta-polypeptide chains'.

Multiple choice botany strategies for enhancement in food production balanced diet food production and microbes plant breeding for food production

By using single-cell protein, amount of protein that can be produced by algae grown in ponds (per acre) is

  1. 20 tons

  2. 30 tons

  3. 40 tons

  4. 50 tons
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A- Single-cell proteins (SCP) are produced by a range of microorganisms and substrate. They are dried cells of microorganism. When SCP is produced, the microbial products produce sufficient proteinaceous substances that can be utilized as protein supplements for animal feeds or human foods. It is estimated that algae grown in ponds can produce 20 tons (dry weight) of protein, per acre, per year.

Multiple choice botany strategies for enhancement in food production balanced diet food production and microbes plant breeding for food production

Which one possesses highest protein content

  1. Spirulina

  2. Glycine max

  3. Arachis hypogea

  4. Pisum sativum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Spirulina is a cyanobacterium known for having an exceptionally high protein content, often ranging from 60 to 70 percent of its dry weight, which is significantly higher than common legumes like peas or peanuts.

Multiple choice bio-chemistry coordination in life processes role of intestine digestion in intestine mechanism of digestion digestive system - organs

The major site of protein breakdown to form free amino acids, is in the

  1. Kidney

  2. Spleen

  3. Intestine

  4. Bone-marrow
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pancreatic juice contains pancreatic amylase, lipase and trypsin, trypsin converts polypeptides into the dipeptides in the first part of small intestine i.e., duodenum. The succus entricus in the third part of small intestine i.e., ileum converts dipeptides into the amino acids which are absorbed by the wall of the intestine. Thus, the correct answer is option C.

Multiple choice bio-chemistry coordination in life processes role of intestine digestion in intestine mechanism of digestion digestive system - organs

End products of protein hydrolysis are

  1. Mixture of amino acids

  2. Sugars

  3. Peptides

  4. 25 amino acids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Proteins are biopolymers made up of  by joining together of amino acids with the help of peptide bonds. When proteins are acted upon by digestive proteolytic enzymes in the gut the peptide bonds are hydrolyzed and a mixture of amino acids is obtained.