GAT Subject Biological Sciences MCQs

Cellular respiration oxidizes fuel molecules.
Most ATP in aerobic cells is produced through oxidative phosphorylation.

The Krebs cycle oxidizes acetyl-CoA.
It produces reduced electron carriers and carbon dioxide.

Photosynthesis builds carbohydrates from carbon dioxide and water.
Light energy is captured by pigments such as chlorophyll.

Phospholipids spontaneously form bilayers in water.
They are the main structural molecules of cell membranes.

Proteins are polymers of amino acids linked by peptide bonds.
Their sequence determines folding and function.

Peptide bonds form through dehydration synthesis.
They link the carboxyl group of one amino acid to the amino group of another.

Heat, pH, or chemicals can disrupt protein folding.
The amino-acid sequence may remain intact.

Enzymes lower activation energy.
They speed reactions without being consumed overall.

The active site has a shape and chemistry suited to its substrate.
Binding promotes the transition state.

Substrates bind to active sites.
They are converted into products during the reaction.

Warming increases molecular collisions up to an optimum.
Excess heat disrupts enzyme structure.

PH alters ionization of amino-acid side chains.
Extreme pH can reduce activity or denature enzymes.