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 biomacromolecules biotechnology cell biology and biotechnology biomolecules biology
Biomolecules are

  1. inorganic materials

  2. organic materials

  3. all the carbon compounds obtained from living tissues

  4. only DNA and RNA
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Biomolecules are basically all the carbon compounds obtained from the living tissue. All the major components that make up a living being that is the carbohydrate, proteins, lipids contain carbon in one form or the other.

Carbon is the structural as well as the functional unit of the basic framework of the cell.

So, the correct option is 'all the carbon compounds obtained from living tissues'

Multiple choice biomacromolecules biotechnology cell biology and biotechnology biomolecules biology

Cellular micromolecules are

  1. Amino acids, Water, Minerals and Sugars

  2. Glycogen, Amino acids, Minerals and Nucleotides

  3. Water, Minerals, Nucleic acids, Amino acids and Nucleotides

  4. Sugars, Water, Minerals, Proteins and Nucleotides
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cellulose micromolecules are small in size and have low molecular weights which is less than 1000 daltons. They have simple molecular structure and often high solubility in the intracellular fluid. These include inorganic compounds such as water, mineral salts, and gases as well as organic compounds such as sugars, lipids, amino acids and nucleotides. The small molecules are the substrates and products of metabolism in the cell. The micromolecules act as building blocks for the macromolecules. 

Thus, the correct answer is option A. 

Multiple choice biomacromolecules biotechnology cell biology and biotechnology biomolecules biology

About 98 percentage of the mass of every living organism is composed of just six elements including carbon, hydrogen, nitrogen, oxygen and

  1. Sulphur and Magnesium

  2. Magnesium and Phosphorous

  3. Calcium and Phosphorous

  4. Phosphorus and Sulphur
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Body needs phosphorus to build and repair bones and teeth.
  • It also helps nerves to function.
  • Calcium is important on blood clotting, muscle contraction, and strengthening bones. 
Multiple choice biomacromolecules biotechnology cell biology and biotechnology biomolecules biology

In which one of the following, the set of items are wrongly paired?

  1. Lysine, glycine, thiamine - Amino acids

  2. Myosin, oxytocin and gastrin - Hormones

  3. Rennin, nuclease and hyaluronidase - Proteolytic enzymes

  4. The nerves that carry signals away from the central nervous system - Afferent neurons
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The nerves responsible for sensing a stimulus and sending information about the stimulus to your central nervous system are called afferent neurons. The nerves that carry signals away from the central nervous system in order to initiate an action are called efferent neurons.

Multiple choice biomacromolecules biotechnology cell biology and biotechnology biomolecules biology

Pick out the wrong statement.

  1. Amino acids are substituted methanes.

  2. Is a trihydroxy propane.

  3. Lysine is a neutral amino acid.

  4. Lecithin is a phospholipid.

  5. Adenosine is a nucleoside.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Amino acids are amphoteric compounds having a carboxylic group, amino group, hydrogen and a substituent group bonded to same carbon atom called the $\alpha$-carbon atom. The substituent group may be having one or more carboxylic groups or amino groups. In case the substituent group is having an extra amino group, the amino acid will be having more than one amino groups and will be positively charged at neutral pH and will be a basic amino acid like lysine and arginine.

Similarly if substituent group carries extra carboxylic group, the amino acid will carry negative charge at neutral pH and will be an acidic amino acid like aspartic acid and glutamic acid.
In case the substituent group does not carry extra carboxylic or amino groups the amino acid is neutral amino acid example glycine, alanine, valine.

Multiple choice biomacromolecules biotechnology cell biology and biotechnology biomolecules biology

Enzyme, vitamins and hormones can be classified into a single category of biological chemicals, because all of these

  1. Decrease metabolism.

  2. Are conjugated proteins.

  3. Are exclusively synthesized in the body of a living organism as at present.

  4. Help in regulating metabolism.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Enzymes, vitamins and hormones are critical to the central role of these elements in the metabolism. Some enzymes in addition to the proteinaceous part require an additional organic molecule coenzyme. Most of the coenzymes are derived from vitamins. Hormones are chemically a diverse group. They may be amines or steroids or peptides. The hormones regulate body metabolism over a longer duration and slowly effect the developmental changes during the development of an organism. The main difference between the enzyme (coenzyme) and hormones is the time scale of their operation. Both are similar in their role in regulating body metabolism.

Multiple choice biomacromolecules biotechnology cell biology and biotechnology biomolecules biology

Purine  base with methyl substituents occurring in plants are

  1. Caffeine

  2. Theophylline

  3. Theobromine

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

A number of purine bases containing methyl substituents occur in plants and plant products and many of them have pharmacological properties. For example Theophylline is chemically 1,3-dimethylxanthine. It is found in tea. Theobromine occurs in cocoa. It is chemically 3,7-dimethylxanthine. Caffeine is present in coffee. It is chemically 1,3,7-trimethylxanthine. 

Multiple choice biology food components and nutrition need for nutrients nutrition and its deficiency nutrition and its need

Nutrition of animals is related to

  1. Trophology

  2. Teratology

  3. Dysteleology

  4. Tricology
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A- Food combining (also known as trophology) is a term for a nutritional approach that advocates specific ingestion and combinations of foods as central to good health and weight loss.
B- Teratology is the medical discipline that focuses on birth defects and congenital abnormalities. Most teratological professionals provide consultative services to pregnant women, or engage in complex research. 
C- Absence of purpose in nature especially as manifested in rudimentary or nonfunctional structures.
D- Trichology is the branch of dermatology concerned with the health of hair and scalp. Trichology helps in diagnosis of the causes of hair fall, hair breakage, hair thinning, miniaturization of hairs, diseases of the scalp and treat the diseases.
So, the correct option is 'Trophology'.
Multiple choice bio-chemistry carbohydrate metabolism metabolism enzymes metabolism, cell respiration, and photosynthesis

Which one of the following is a catabolic process? 

  1. Regulation

  2. Photosynthesis

  3. Digestion

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

Metabolism refers to series of reactions in which product of one reaction becomes reactant for the next one. It includes catabolism (degradative pathways) and anabolism (synthetic pathways). Digestion is the process in which complex compounds are broken down into the simpler form. Hence, option C is the correct answer. 

Multiple choice biology metabolism, cell respiration, and photosynthesis metabolism enzymes carbohydrate metabolism

Which statement regarding enzyme inhibition is correct?

  1. Competitive inhibition occurs when a substrate competes with enzyme for binding to inhibitor protein

  2. Competitive inhibition occurs when the substrate and the inhibitor compete for active site on the enzyme

  3. Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate

  4. Non-competitive inhibitors often bind to the enzyme irreversibly
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
A molecule similar to substrate competes with the substrate for active site. Such molecules are known as inhibitor. The presence of the inhibitor decreases availability of the active site for the substrate and further decreases the rate of reaction. This inhibition is known as competitive inhibition.
For example, malonate acts as a inhibitor which  competes with the succinate and prevents its attachment to the enzyme succinate dehydrogenase.
So, the correct answer is option B.
Multiple choice biology metabolism, cell respiration, and photosynthesis metabolism enzymes carbohydrate metabolism

Nerve gas (DFP) inhibits neurotransmission as it reacts with

  1. Serine of acetylcholine-esterase.

  2. Choline of acetylcholine-esterase.

  3. Acetylcholine.

  4. Noradrenaline.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Nerve gas attacks the nervous system of the human body. All such gases function in the same way, it inhibits the enzyme acetylcholine esterase by reacting with the active site of serine, and is responsible for the breakdown of the acetylcholine in the synapse.
So, the correct answer is A.
Multiple choice biology metabolism, cell respiration, and photosynthesis metabolism enzymes carbohydrate metabolism

Identify the correct statement regarding enzyme inhibition.

  1. Non-competitive inhibition of an enzyme can be overcomed by adding large amount of substrate.

  2. Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein.

  3. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme.

  4. Non-competitive inhibitors often bind to the enzyme irreversibly.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Competitive inhibition is the inhibition of an enzyme by an inhibitor which has structural similarity to the active site and thus competes with the substrate for binding with the active site. Competitive inhibition is a reversible inhibition and depends on the relative concentration of substrate and inhibitor.

Multiple choice biology metabolism, cell respiration, and photosynthesis metabolism enzymes carbohydrate metabolism

Which of the following is true?
Non-competitive inhibitor differs from a competitive inhibitor in that it

  1. Reduces the affinity of substrate for enzymes
  2. Does not alter K$ _m$

  3. May attach it self to the enzyme at a site other than the active site

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A non-competitive inhibitor is one that binds to a site distinct from the site which binds the substrate; inhibitor binding does not block substrate binding or vice versa. The enzyme is inactivated when inhibitor is bound, whether or not substrate is also present. The inhibitor effectively lowers the concentration of active enzyme and hence, lowers the apparent V$ _{max}$. There is often little or no effect on K$ _m$.