Biomolecules

Which biomolecule acts as the immediate source of energy for cellular activities?

1. Cellulose
2. Glucose
3. Cholesterol
4. DNA

Which nitrogenous base is found in RNA but absent in DNA?

1. Adenine
2. Cytosine
3. Uracil
4. Guanine

Glycogen is mainly stored in:

1. Plant leaves
2. Animal liver and muscles
3. Fungal spores only
4. Plant roots only

Which factor does NOT usually affect enzyme activity?

1. Temperature
2. pH
3. Substrate concentration
4. Colour of the substrate

Enzymes are chemically classified as:

1. Carbohydrates only
2. Proteins in most cases
3. Lipids
4. Vitamins

Which level of protein structure represents the sequence of amino acids?

1. Primary structure
2. Secondary structure
3. Tertiary structure
4. Quaternary structure

The basic structural unit of nucleic acids is:

1. Amino acid
2. Fatty acid
3. Monosaccharide
4. Nucleotide

Which enzyme catalyzes the breakdown of proteins into peptides?

1. Amylase
2. Lipase
3. Protease
4. Maltase

Which lipid forms the basic framework of the plasma membrane?

1. Triglycerides
2. Waxes
3. Phospholipids
4. Cholesterol only

Which of the following is a reducing sugar?

1. Sucrose
2. Lactose
3. Cellulose
4. Starch

Which polysaccharide is the major structural component of plant cell walls?

1. Glycogen
2. Starch
3. Cellulose
4. Maltose

Which carbohydrate serves as the primary storage polysaccharide in plants?

1. Glycogen
2. Cellulose
3. Chitin
4. Starch

Which bond joins two amino acids together?

1. Glycosidic bond
2. Ester bond
3. Peptide bond
4. Hydrogen bond

The monomeric unit of proteins is:

1. Monosaccharide
2. Fatty acid
3. Amino acid
4. Nucleotide

Which of the following is the most abundant biomolecule found in living cells by dry weight?

1. Lipids
2. Proteins
3. Carbohydrates
4. Nucleic acids