SQA course specification flashcards Unit 2

What are metabolic pathways?

Integrated and controlled enzyme-catalysed reactions within a cell.

What types of steps can metabolic pathways include?

Reversible steps, irreversible steps, and alternative routes.

What are anabolic reactions?

Reactions that build large molecules from small ones and require energy

What are catabolic reactions?

Reactions that break down large molecules into smaller ones and release energy.

What types of proteins are embedded in membranes?

Protein pores, pumps, and enzymes.

What controls metabolic pathways?

Presence/absence of enzymes and regulation of key enzyme activity.

What is induced fit in enzymes?

The enzyme's active site changes shape to better fit the substrate.

How does the active site affect a reaction?

It lowers activation energy and affects affinity for substrate and product.

How does substrate concentration affect enzyme activity?

Higher substrate concentration can increase the rate and direction of reaction.

What are three types of enzyme inhibition?

Competitive, non-competitive, and feedback inhibition.

What is glycolysis?

The breakdown of glucose to pyruvate in the cytoplasm.

What happens during the energy investment phase of glycolysis?

ATP phosphorylates glucose and intermediates.

What is the outcome of glycolysis?

A net gain of ATP.

What happens to pyruvate in aerobic conditions?

It's broken down into an acetyl group which joins with Coenzyme A to form acetyl CoA.

What does acetyl CoA do in the citric acid cycle?

Combines with oxaloacetate to form citrate.

What does the citric acid cycle produce?

ATP and CO2.

Where does the citric acid cycle occur?

In the mitochondrial matrix.

What do dehydrogenase enzymes do?

Remove hydrogen ions/electrons and pass them to NAD forming NADH.

What happens to NADH?

It donates electrons to the electron transport chain.

How is energy released in the electron transport chain?

Electrons move along the chain releasing energy.

What does the energy released in the electron transport chain do?

Pumps hydrogen ions across the inner mitochondrial membrane.

What happens as hydrogen ions flow back?

ATP synthase uses the flow to produce ATP.

What happens to the electrons and hydrogen ions?

They combine with oxygen to form water.

Where does fermentation occur?

In the cytoplasm.

What does pyruvate convert into in animals?

Lactate (reversible).

What does pyruvate convert into in yeast/plants?

Ethanol and CO2 (irreversible).

How does fermentation compare to aerobic respiration?