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 bio-chemistry diseases and immunity antibodies antibodies and antitoxin antigen and antibody

Binding of antigen to antibody is through

  1. Electrostatic intereactions

  2. Covalent bonds

  3. Disulphide bridges

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

Antibodies bind antigens through weak chemical interactions, and bonding is essentially non-covalent. Electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions are all known to be involved depending on the interaction sites.

So, the correct answer is 'Electrostatic intereactions'.

Multiple choice zoology locomotion and movement contractile protein structure of muscle muscles and their structure

State whether the following statements are true or false.
Actin is actually a globular protein that assembles as a long beady structure consisting of two helical chains.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Skeletal muscle is composed of muscle fibres which have smaller units called myofibrils. There are three types of proteins make up each myofibril; they are contractile, regulatory and structural proteins. By contractile proteins, we mean actin (thin filament), a globular protein assembling with a long beady structure consisting chains and myosin (thick filament).

So, the correct option is 'True'.

Multiple choice zoology locomotion and movement contractile protein structure of muscle muscles and their structure

Choose the correct answer from the alternatives given.
The enormous diversity of protein molecules is mostly due to the diversity of:

  1. Amino groups on the amino acids

  2. K groups on the amino acids

  3. R groups on the amino acids

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

There are 20 amino acids known. All the amino acids follow the basic structure. It consists of a carbon atom in the middle surrounded by three chemical bases.

Two out of three bases are the amino (NH$ _2$ group) and the carboxylic group (COOH). The third group is a simple hydrogen atom present in all the amino acids.
The fourth group is called an R group that determines the nature of the amino acid. This R group can be as simple as a hydrogen atom and may also contain complex rings. On the basis of the R group, the amino acid can be polar or non-polar, acidic or basic or neutral.
Thus the enormous diversity of protein molecules is mostly due to the diversity in the R group.
So, the correct option is 'R groups on the amino acids'.

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Which of the following is not a structural protein?

  1. Fibrin

  2. Albumin

  3. Collagen

  4. Keratin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fibrous proteins which are most familiar, and  are probably the keratins, which form the protective covering of all land vertebrates: skin, fur, hair, wool, claws, nails, hooves, horns, scales, beaks and feathers. Albumin is not a structural protein.

So, the correct option is 'Albumin'.

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Positively regulatory proteins are called _____________.

  1. activator

  2. repressors

  3. necessary proteins

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

The activator proteins bind to the operator site on the m-RNA to start the process of transcription. This is called as positive regulation since it starts the transcription process and hence the activator protein is called positively regulatory proteins.

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Which of the following enzymatic protein of cilia & flagella is similar to muscle cells ?

  1. Lamin protein

  2. Nexin protein

  3. Spectrin protein

  4. Dynein protein
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Dynein is a motor protein found in cilia and flagella that is structurally and functionally analogous to myosin in muscle cells, interacting with microtubules to cause bending and movement. It exhibits ATPase activity similar to muscle contractile proteins.

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Which of the following protein plays an important role in ageing 

  1. Elastin

  2. Collagen

  3. Actin

  4. Myosin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Collagen is the most abundant extracellular protein which with ageing becomes less permeable, less flexible and insoluble. These changes interfere the normal functioning of the cells (decreased inflow of nutritive substances and oxygen into cells and also decreased loss of nitrogenous waste and $CO _{2}$ from the body cells) and induce ageing.

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Degradation of proteins play a part in ____________.

  1. Calvin cycle

  2. Water cycle

  3. Sulphur cycle

  4. Nitrogen cycle
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Plants and animals contain nitrogen in their body Protein' After death, the Proteins of dead bodies are decomposed into amino acids and ammonia. This ammonia may be converted into nitrates or free Nitrogen'
So, the correct answer is 'Nitrogen cycle'
Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Those amino acids that cannot be synthesized by the body and must be derived through the diet are known as

  1. coenzymes

  2. essential amino acids

  3. polypeptides

  4. non-essential amino acids
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Essential amino acids are not produced in the body, so they are to be taken from outside.
  • There are 9 essential amino acids; Histidine, isoleucine, leucine, valine, threonine, tryptophan, phenylalanine
So, the correct answer is 'Essential amino acids'

Multiple choice evs nutritious food minerals and vitamins nutrition and diet role of various nutrients

Non-protein part of the conjugated protein is called.......

  1. co-factor

  2. ketone

  3. prosthetic group

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

Enzymes with protein and non protein part is called conjugated enzyme. It is also called holoenzyme. In this, protein part is called apoenzyme and non protein part is called co-factor. In the co-factor, organic co-factors are called co-enzymes and inorganic co-factors are called metal ions.

So, the correct option is 'co-factor'.