R4RIN – MCQs, Mock Tests | Aptitude Aptitude Mcq Questions Kingdom Monera

Enzymes _________ the activation energy of a chemical reaction

1. Increases
2. Decreases
3. Does not effect
4. Increases or decreases depending upon individual enzyme

✅ Correct Answer: 2

A three dimensional dcavity bearing a specific charge by which the enzyme reacts with its substrate is called

1. Active site
2. Binding site
3. Catalytic site
4. Allosteric site

✅ Correct Answer: 1

Which step causes activation of catalytic site of an enzyme?

1. Change in pH of the surroundings.
2. Formation of Enzyme Susstrate complex.
3. Change in the charge of the active site.
4. Change in temperature

✅ Correct Answer: 2

Lock and Key model was proposed by

1. Emil Fischer
2. Koshland
3. Robin Williams
4. Rudolph Virchow

✅ Correct Answer: 1

Which statement is incorrect about Lock and Key Model?

1. Specific enzyme can transform only a specific substrate
2. Active site of an enzyme is a non flexible structure.
3. Active site does not change before during or even after the reaction.
4. It explains the mechanism of every chemical reaction.

✅ Correct Answer: 4

The rate of reaction is directly proportional to the concentration of an enzyme which statement is incorrect in this respect:

1. Increase in enzyme molecule increases the available active sites.
2. This relation is for unlimited time period with unlimited enzyme concentration
3. If the concentration is doubled the rate will become two fold.
4. None of these.

✅ Correct Answer: 2

If the concentration of enzyme is kept constant and amount of substrate is increased a point is reached where increase in substrates concentration does not affect the reaction rate because of

1. Enzymes get denatured at higher substrate conc.
2. Rate of reaction is indirectly proportional to substrate concentration at this point.
3. All the active sites on enzyme molecule are occupied.
4. None of these.

✅ Correct Answer: 3

If more substrate to already occurring enzymatic reaction is added more enzyme activity is seen because:

1. There is probably more substrate present than there is enzyme.
2. There is probably more enzayme available than there is substrate.
3. There is probably more product present than there is either substrate or enzyme.
4. The enzyme substrate complex is probably failing to form during the reaction.

✅ Correct Answer: 2

If more substrate to already occurring enzymatic reaction is added and there is no effect on the rate of the reaction what is the form given to this situation:

1. Saturation
2. Denaturation
3. Composition
4. Inhibition

✅ Correct Answer: 1

The active site of an enzyme:

1. Never changes
2. Forms no chemical bond with substrate
3. Determined by structure and the specificity of the enzyme.
4. They are non specific in their action.

✅ Correct Answer: 3

Excessive increase in temperature of medium causes the enzyme molecule to

1. Activate
2. Unaffected
3. Denatured
4. None of these.

✅ Correct Answer: 3

Extreme change in pH results in:

1. Change in ionization of amino acids at the active site of the enzyme.
2. Change in the ionization of the substrate.
3. Denaturation of the enzyme
4. Increase in the reaction rate

✅ Correct Answer: 3

Optimal temperature of enzymes present in human body is

1. 27?C
2. 37?C
3. 47?C
4. 30?C

✅ Correct Answer: 2

A chemical substance which can react (in place of substrate) with the enzyme but is not transformed into product/s and thus blocks the active site temporarily or permanently is called

1. Co-enzyme
2. Blocker
3. Inhibitor
4. Cofactor

✅ Correct Answer: 3

Inhibitors which block the enzyme by forming weak bond are called

1. Competitive inhibitors.
2. Non-competitive inhibitors
3. Irreversible inhibitors.
4. Both a and b

✅ Correct Answer: 4

A substance which binds at the active site of the enzyme but does not result in the formation of the products is called:

1. Irreversible inhibitor
2. Reversible inhibitor
3. Competitive inhibitor
4. Non-competitive inhibitor

✅ Correct Answer: 3

The structure of an enzyme is altered by:

1. Irreversible inhibitor
2. Reversible inhibitor
3. Competitive inhibitor
4. Non-competitive inhibitor

✅ Correct Answer: 1

Malonic acid is an example of:

1. Irreversible inhibitor
2. Reversible inhibitor
3. Competitive inhibitor
4. Non-competitive inhibitor

✅ Correct Answer: 3

If enzyme concentration is low than substrate pH and temperature values are equal to requirement then which of the following will increase rate of reaction.

1. increase in concentration of enzyme
2. increase in concentration of substrate
3. increase in pH
4. increase in temperature

✅ Correct Answer: 1

The word Archaeobacteria (a division of bacteria) derived from Greek means

1. True bacteria
2. False bacteria
3. Recent bacteria
4. Ancient bacteria

✅ Correct Answer: 4

Who coined the term Animalcules for microorganisms like Bacteria and protozoa?

1. Robert Koch
2. Louis Pasteur
3. Alexander Fleming
4. Leeuwenhoek

✅ Correct Answer: 4

Who discovered the bacteria causing tuberculosis and also developed various techniques of media preparation and maintenance of pure culture?

1. Robert Koch
2. Louis Pasteur
3. Alexander Fleming
4. Leeuwenhoek

✅ Correct Answer: 1

Which of the following statement is incorrect regarding germ theory of diseases postulated by Robert Koch?

1. A specific organism can always be found in association with a given disease
2. The organism can be isolated and grown in pure culture in the laboratories
3. The pure culture cannot produce the disease when inoculated into susceptible animal however the causative organism isolated from pure culture can do so.
4. It is possible to recover the organism in pure culture from the experimentally infected animals.

✅ Correct Answer: 3

Which of the following structure is not present in all the bacteria?

1. Cell membrane
2. Chromatin bodies
3. Ribosomes
4. Capsule

✅ Correct Answer: 4

The size of Spirochete is

1. 0.1 -600 um
2. 100-200 nm
3. 500 um
4. 0.75-1.25 um

✅ Correct Answer: 3

E. coli and example of entrobacteriace is important for causing diarrheal diseases its size is:

1. 0.1-600 um
2. 100-200 nm
3. 1.1-1.5 um (width) 2.0-6.0 um (length)
4. 0.75-1.25 um

✅ Correct Answer: 3

In bacterial categories the bacteria smaller in number are

1. Gram-ive bacteria
2. Gram-ive bacteria
3. Ancient bacteria
4. Gram +ive bacteria

✅ Correct Answer: 3

Germ theory of disease has ______ postulates

1. 3
2. 5
3. 4
4. 6

✅ Correct Answer: 3

Some bacteria ranging occasionally a size of 500 ?m in length are

1. Escherichia coli
2. Spirochetes
3. Mycoplasma
4. Epulopiscuim

✅ Correct Answer: 2

Coccobacillus has a shape similar to

1. Diplobacillus
2. Sarcina
3. Egg
4. None of these

✅ Correct Answer: 3

The first bacterium isolated was

1. Coccus
2. Bacillus
3. Vibrio
4. Spirochete

✅ Correct Answer: 2

Which of the following bacteria are thick rigid and spiral?

1. Vibrio
2. Spirillum
3. Spirochete
4. Coccus

✅ Correct Answer: 2

Coccus

1. Diplococci
2. Octococci
3. Tetrad
4. Sarcina

✅ Correct Answer: 4

Which of the following has a chain arrangement?

1. Streptobacillus
2. Streptococci
3. Staphylococci
4. Both A and B

✅ Correct Answer: 4

Which of the following bacteria do not have flagella commonly?

1. Cocci
2. Bacilli
3. Streptobacilli
4. Vibrio

✅ Correct Answer: 1

Flagella originate from

1. Cell membrane
2. Cell wall
3. Capsule
4. Basal body

✅ Correct Answer: 4

A bacterium with tuft of flagella at both poles is called

1. Lophotrichus
2. Monotrichous
3. Peritrichous
4. Amphitrichous

✅ Correct Answer: 4

Which of the following structure primarily helps in attachment of bacteria on various surfaces?

1. Flagella
2. Pili
3. Both of these
4. None of these

✅ Correct Answer: 2

Which of the following structure provides greater pathogenicity to the bacteria?

1. Capsule
2. Slime
3. Cell Wall
4. Cell membrane

✅ Correct Answer: 2

Cell wall is absent in

1. Cocci
2. Bacilli
3. Mycobacterium
4. Mycoplasma

✅ Correct Answer: 4

Cell wass of Archaeobacteria does not contain

1. Peptidoglycan
2. Proteins
3. Glycoproteins
4. Polysaccharides

✅ Correct Answer: 1

Gram positive bacteria appear

1. Purple
2. Red
3. Pink
4. Blue

✅ Correct Answer: 1

Extremely long molecule of DNA that is tightly folded to fit inside the cell component is called

1. Nucleus
2. Chromosome
3. Chromatid
4. Chromatin body

✅ Correct Answer: 4

Which of the following contains genes for drug and disease resistance in bacteria?

1. Necleotide
2. Plasmid
3. Mesosome
4. Ribosome

✅ Correct Answer: 2

The common waste material in bacteria is

1. Glycogen
2. Lactic acid
3. Ammonia
4. Urea

✅ Correct Answer: 2

Example of bacteria requiring low concentration of oxygen is

1. Campylobactor
2. spirocheta
3. E-coli
4. Pseudomonas

✅ Correct Answer: 1

Purple non-sulphur bacteria is an example of

1. Heterotrophic bacteria
2. Chemosynthetic bacteria
3. Photosynthetic bacteria
4. Saprotrophic bacteria

✅ Correct Answer: 3

Those bacteria which are fully dependent upon their host for nutrition are called

1. Heterotrophic bacteria
2. Chemosynthetic bacteria
3. Saprophytic bacteria
4. Parasitic bacteria

✅ Correct Answer: 4

Nitrifying bacteria are the examples of

1. Hetrotrophic bacteria
2. Chemosynthetic bacteria
3. Saprophytic bacteria
4. Parasitic bacteria

✅ Correct Answer: 2

E. coli and example of

1. Aerobic bacteria
2. Anaerobic bacteria
3. Facultative bacteria
4. Microaerophilic

✅ Correct Answer: 3