Biosynthetic Pathways

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Cytoplasm

Where do most anabolic reactions occur in the cell?

They always use the same enzymes

Which of the following is not a difference between biosynthetic and degradative pathways?

HMG-CoA reductase

What is the key enzyme that catalyzes the committed step in cholesterol synthesis?

UTP

Which molecule activates glucose to UDP-glucose in carbohydrate biosynthesis?

Cori Cycle

What process allows glucose synthesis from lactate in animals?

Glucose

What is the primary product of photosynthesis that is later converted into other carbohydrates?

Acetyl-CoA and malonyl-CoA

Fatty acids are synthesized using

Acyl carrier protein (ACP)

What complex carries the growing fatty acid chain during synthesis?

Glycogenesis

Which process converts glucose into glycogen?

Cannot be synthesized by the body and must come from diet

Which of the following is an essential amino acid?

Cholesterol synthesis

begins with acetyl-CoA.

Glutamate

is synthesized by amination and reduction of α-ketoglutarate.

amino acids

are derived from glycolysis or citric acid cycle intermediates.

Malonyl-CoA

Which molecule is formed from acetyl-CoA and CO₂ during fatty acid synthesis?

NADPH

Which coenzyme is primarily used in the reduction reactions of fatty acid synthesis?

Dihydroxyacetone phosphate

What molecule is reduced to form glycerol 1-phosphate in lipid biosynthesis?

Liver

Which organ primarily synthesizes cholesterol for the body?

Mevalonate pathway

Which metabolic pathway uses acetyl-CoA as the main building block for cholesterol?

Glucose-6-phosphatase

Which enzyme converts glucose-6-phosphate to glucose during gluconeogenesis?

A saturated acyl-ACP chain 2 carbons longer

In fatty acid synthesis, what is the product of each full cycle before another C₂ unit is added?

Isopentenyl pyrophosphate

Which molecule initiates the biosynthesis of isoprenoids like cholesterol?

Makes them more hydrophobic and membrane-mobile

What does prenylation do to proteins?

Synthesis of glucose from non-carbohydrate sources

Which of the following best defines gluconeogenesis?

Sphingolipids and glycolipids

are built from fatty acids and specific backbones.

Acetyl-CoA

Starting molecule for cholesterol

Cori Cycle

Muscle-to-liver lactate conversion

ACP (Acyl Carrier Protein)

Enzyme complex in fatty acid synthesis

Pyruvate carboxylase

Converts pyruvate to oxaloacetate

Gluconeogenesis

NADH oxidized to NAD⁺

Essential amino acids

What type of amino acids must be obtained from the diet?

α-Ketoglutarate

Which citric acid cycle intermediate is used to synthesize glutamate?

Pyridoxal phosphate (PLP)

Which coenzyme is involved in many transamination reactions?

HMG-CoA

What compound is formed by combining three acetyl-CoA molecules during cholesterol synthesis?

Mevalonate

Which molecule is the direct product of HMG-CoA reduction in cholesterol biosynthesis?

Geranyl and farnesyl pyrophosphate

What are the names of the C10 and C15 intermediates in cholesterol synthesis?

Squalene

What major molecule do farnesyl pyrophosphates condense to form during cholesterol synthesis?

Reductive amination

Which pathway converts α-ketoglutarate to glutamate?

Serine

Which amino acid is a precursor for membrane lipid biosynthesis (e.g., phosphatidylserine)?

A phosphate group on the 3' carbon of ribose

What structural feature makes NADPH different from NAD⁺?

Cholesterol

is a precursor to steroid hormones and bile acids.

Protein prenylation

enhances membrane association and movement.

Serine

plays a role in both lipid and amino acid biosynthesis.

Glutamate

Intermediate amino acid for transamination

Isopentenyl pyrophosphate

5-carbon unit for building steroids

Squalene

Final product of cholesterol biosynthesis

Pyruvate carboxylase

Enzyme for pyruvate to oxaloacetate

Farnesyl pyrophosphate

15-carbon intermediate in cholesterol pathway