Nicotinamide Nucleotide Transhydrogenase

The video explores the mechanisms of cytochrome C oxidase in the respiratory chain, focusing on the formation of reactive intermediates like superoxide. It explains how enzymes like superoxide dismutase, glutathione peroxidase, and glutathione reductase work together to neutralize these radicals, protecting the body from damage. The role of nicotinamide nucleotide transhydrogenase in generating NADPH for reducing glutathione is also discussed, highlighting the body's antioxidant defense system.

What is the primary function of cytochrome C oxidase in the respiratory chain?

• To synthesize ATP

• To transport electrons and reduce oxygen to water

• To oxidize NADH

• To generate superoxide radicals

What happens when cytochrome C oxidase fails to hold onto oxygen during reduction?

• It forms ATP

• It stops the electron transport chain

• It produces hydrogen gas

• It releases a superoxide radical

Which enzyme is responsible for converting superoxide radicals into hydrogen peroxide?

• Glutathione peroxidase

• Cytochrome C oxidase

• Superoxide dismutase

• NADPH oxidase

Why is hydrogen peroxide considered harmful in the body?

• It is a potent oxidizing agent

• It can form hydroxide radicals

• It is a strong acid

• It blocks electron transport

What is the role of glutathione peroxidase in the cell?

• To transport electrons

• To synthesize ATP

• To reduce hydrogen peroxide to water

• To oxidize glutathione

What is unique about the synthesis of glutathione?

• It is synthesized by ribosomes

• It is a monosaccharide

• It is a dipeptide

• It is synthesized by enzymes, not ribosomes

Which enzyme helps regenerate reduced glutathione using NADPH?

• Superoxide dismutase

• Glutathione reductase

• Glutathione peroxidase

• Nicotinamide nucleotide transhydrogenase

What is the role of nicotinamide nucleotide transhydrogenase in the mitochondria?

• To oxidize NADPH

• To convert NADH to NADPH

• To synthesize ATP

• To transport electrons

Which of the following is NOT an antioxidant mentioned in the video?

• Glutathione

• Hydrogen peroxide

• Vitamin E

• Ascorbic acid

What is the main purpose of the enzymatic processes discussed in the video?

• To protect the body from free radicals

• To transport oxygen

• To synthesize proteins

• To produce ATP