Biochemistry Exam Review Flashcards

These flashcards cover key vocabulary and concepts from the Biochemistry exam review, focusing on metabolic pathways, enzyme functions, and hormonal regulation.

Malic enzyme

An enzyme that plays a role in cellular metabolism and exhibits decreased chemical capabilities in some cells.

ATP-citrate lyase deficiency

A condition where cells show no success in identifying a deficiency of this enzyme, which is crucial for lipid metabolism.

Glucagon

A hormone that decreases the activity of HMG-CoA reductase and increases the activity of triacylglycerol lipase during fasting states.

Acetoacetate

A ketone body that acts as a metabolic fuel for isolated heart cells, allowing them to contract in the absence of glucose.

Citric acid cycle

A central metabolic pathway that may slow down in heart cells unless pyruvate is supplied.

Acetyl-CoA carboxylase

The principal regulatory enzyme in fatty acid synthesis; its activity can be influenced by citrate levels.

Insulin receptor

A protein that, when bound by insulin, affects the activity of enzymes such as acetyl-CoA carboxylase in liver cells.

AMP-dependent kinase

An enzyme that, when activated, can phosphorylate various metabolic enzymes changing their activity levels.

Malonyl-CoA

A molecule crucial for fatty acid metabolism that inhibits fatty acid breakdown by preventing their entry into mitochondria.

Pyruvate carboxylase

An enzyme that converts pyruvate to oxaloacetate in the mitochondrial matrix; deficiencies lead to the accumulation of ketone bodies.

Carnitine acyltransferase

An enzyme involved in the transport of fatty acids into mitochondria; mutations can impair fatty acid oxidation.

Cholesterol levels

The concentration of cholesterol in the liver, which influences the behavior of proteins such as Insig, SCAP, and SREBP.

ATP in cell survival

A critical molecule necessary for cell growth and maintenance, supporting ion balance and nutrient uptake.

Insig

A protein that retains SREBP in the endoplasmic reticulum when cholesterol levels are low.

SCAP

A protein that binds Insig and regulates SREBP based on cholesterol levels.

SREBP

A transcription factor that is activated when cholesterol levels are low, allowing for the expression of genes involved in cholesterol synthesis.