Nutritional Biochemistry Long Exam 2 (copy)

Glucagon

A hormone that increases blood glucose levels by mobilizing and liberating fuel stores.

Insulin

A hormone that decreases blood glucose levels by storing and conserving energy fuels.

Synthesis

The process of producing or creating something.

Plasma Levels

The concentration of a substance in the liquid component of blood.

Basal

Referring to the body's baseline or resting state.

Diabetes

A chronic condition characterized by elevated blood glucose levels.

Type I Diabetes symptoms

Insulin-dependent diabetes mellitus (IDDM) that typically presents itself at a younger age and requires insulin injections for treatment.

Type II Diabetes symptoms

Non-insulin-dependent diabetes mellitus (NIDDM) that typically presents itself in individuals over the age of 30 and can be managed through nutritional intervention and weight reduction.

Anoxic Episodes in Muscle

Episodes of low oxygen levels in muscle tissue.

Energy Flux

The flow and exchange of energy within the body.

C-peptide

A peptide that is removed during the synthesis of insulin and can be used as an indicator of pancreatic function.

Cyclic AMP

A molecule that increases in concentration in response to glucagon and activates various protein kinases.

Tyrosine Kinase

An enzyme that phosphorylates tyrosine residues in proteins.

PI3-kinase

A signaling pathway activated by insulin that plays a role in glucose transport and gene transcription.

Ras Signaling Pathway

A signaling pathway activated by insulin that regulates cell growth and differentiation.

GLUT-4

A glucose transporter protein that is translocated to the plasma membrane in response to insulin.

Glucagon Receptor

A membrane-bound protein that binds to glucagon hormone and activates signaling pathways.

Adenylate Cyclase

An enzyme that synthesizes cyclic AMP in response to activation by G protein.

Glucose Tolerance Test

A test used to diagnose diabetes by measuring how the body responds to a glucose load.

Type 1 diabetes

A form of diabetes characterized by the absence of insulin and destruction of pancreatic β-cells by white blood cells.

Insulin

A hormone produced by the pancreas that allows glucose to enter cells and regulates blood glucose levels.

Type 2 diabetes

A form of diabetes characterized by insulin resistance and impaired glucose metabolism.

Insulin resistance

A condition where muscle and adipose tissues are non-responsive to insulin.

Glycemic Index

A ranking system that measures how much a carbohydrate-containing food raises blood sugar levels.

Low GI

Carbohydrates with a glycemic index below 55.

Medium GI

Carbohydrates with a glycemic index between 56-69.

High GI

Carbohydrates with a glycemic index above 70.

Energy Metabolism

The process by which the body converts food into energy for various organs.

Brain

The organ that primarily uses glucose as its main fuel source.

Liver

The organ that primarily uses fatty acids as its main fuel source and synthesizes and releases glucose for other organs.

Exercising Muscle

Muscle that undergoes complete oxidation of both glucose and fatty acids for energy.

Muscles during Anoxic Episodes

Muscles that produce lactic acid from glucose when there is not enough oxygen.

Enzyme

A protein that catalyzes biochemical reactions in the body.

Glycogen phosphorylase

An enzyme that converts glycogen into glucose.

Glycogen synthase

An enzyme that converts glucose into glycogen.

Glycogen

Storage form of carbohydrates in the liver and muscle.

Glycogen synthase

Enzyme responsible for synthesizing glycogen.

Glycogen phosphorylase

Enzyme responsible for breaking down glycogen.

UDP-glucose

A molecule used in the synthesis of glycogen.

Glucose-1-phosphate

A molecule produced during glycogen breakdown.

Glucagon

Hormone that decreases glycogen synthase activity and increases glycogen phosphorylase activity.

cAMP

A secondary messenger that mediates the effects of glucagon.

G6P

Glucose-6-phosphate, a molecule involved in glucose metabolism.

Glucose-6-phosphatase

Enzyme responsible for converting G6P to free glucose in the liver.

Epinephrine

Hormone released during exercise that activates adenylate cyclase.

Glycolysis

Metabolic pathway that converts glucose into pyruvate.

Gluconeogenesis

Metabolic pathway that synthesizes glucose from non-carbohydrate sources.

Hexokinase

Enzyme that converts glucose to G6P.

Krebs Cycle

Also known as the citric acid cycle, a series of reactions that generates energy from carbohydrates, fats, and proteins.

Dihydroxyacetone phosphate

An intermediate molecule in fructose and glycerol metabolism.

PEPCK

Phosphoenolpyruvate carboxykinase, an enzyme involved in gluconeogenesis.

Pyruvate kinase

Enzyme that catalyzes the conversion of phosphoenolpyruvate to pyruvate.

Phosphofructokinase-1

Enzyme that regulates the rate of glycolysis.

β-oxidation

Metabolic pathway that breaks down fatty acids to produce acetyl-CoA.

TAGs

Triacylglycerols, a form of stored fat.

VLDLs

Very low-density lipoproteins, particles that transport lipids in the bloodstream.

AV Difference

Arteriovenous difference, the difference in concentration of a metabolite between arterial and venous blood.

Clearance Rate

The rate at which a metabolite is taken up by an organ.

Creatine phosphate

A molecule used for short bursts of energy.

Respiratory quotient

A measure of the ratio of carbon dioxide produced to oxygen consumed during metabolism.

Fuel Rate of Use

The rate at which fuel is utilized during different levels of exercise.

Glucose

A type of sugar that is reserved for the brain and is an important energy source during exercise.

FFAs

Free fatty acids that are supplied by adipose tissue and serve as a fuel source during mild exercise.

Creatine Phosphate

A molecule that serves as an "energy buffer" in muscle and helps maintain a constant ATP level during sudden bursts of exercise.

Glycogen

A form of stored glucose in the muscles and liver that is used as a fuel source during exercise.

Carbohydrate Loading

A strategy of consuming carbohydrates after exercise to replenish muscle glycogen stores.

Gluconeogenesis

The process of synthesizing glucose from non-carbohydrate sources, such as lactate, glycerol, and amino acids.

Alanine

An amino acid that is released from muscle during exercise and contributes to gluconeogenesis in the liver.

Glucose Transporters

Proteins that increase in number during exercise to facilitate the uptake of glucose into muscle cells.

Fructose

A type of sugar that is converted to glucose in the liver and can contribute to glycogen synthesis.

Hydrolysis

The process of breaking down TAGs into fatty acids and glycerol.

Hormone-sensitive lipase

An enzyme that catalyzes the hydrolysis of TAGs into fatty acids and glycerol.

FFAs

Free fatty acids, which are released during the hydrolysis of TAGs.

Glycerol

A component of TAGs that can be released during hydrolysis and used for gluconeogenesis.

Glucagon

A hormone that increases the rate of cAMP in cells, leading to increased mobilization of fuel cells.

Epinephrine

A hormone that increases the rate of cAMP in cells, leading to increased mobilization of fuel cells. It increases only during exercise.

cAMP

Cyclic adenosine monophosphate, a signaling molecule that increases the mobilization of fuel cells.

Glycerol Metabolism

The process of utilizing glycerol released during TAG hydrolysis.

Glycerol kinase

An enzyme that converts glycerol to glycerol phosphate.

Glycerol phosphate

A molecule that is converted to dihydroxyacetone phosphate during glycerol metabolism.

Fatty Acid Transport

The process of transporting free fatty acids in the bloodstream.

Albumin

A protein used in the transport of FFAs in the bloodstream.

Membrane-bound proteins

Proteins that mediate the transfer of FFAs across cell membranes.

Fatty acyl-CoA

A form of fatty acids that are converted within cells.

Carnitine

A molecule required for the transport of long-chain fatty acids into the mitochondria.

Krebs Cycle

A metabolic pathway that generates energy from the breakdown of acetyl-CoA.

Medium-chain fatty acids

Fatty acids that are more soluble in water and tend to be metabolized immediately in the mitochondria.

Long-chain fatty acids

Fatty acids that are less soluble in water and are stored as fat.

Anaerobic vs Aerobic Energy Metabolism

The comparison between energy metabolism that occurs in the absence of oxygen (anaerobic) and energy metabolism that occurs in the presence of oxygen (aerobic).

Lactate Dehydrogenase

An enzyme that converts pyruvate to lactate during anaerobic glycolysis.

Ketogenesis

The process by which ketone bodies, such as β-hydroxybutyrate, acetoacetate, and acetone, are produced from fatty acids.

Fasting

A period of time during which an individual abstains from consuming food.

Severe Malnutrition

A condition characterized by a severe lack of energy and protein, resulting in overall wasting of the body.

Malnutrition Types

The two types of severe malnutrition:Marasmus, which is an overall lack of energy and protein, and Kwashiorkor, which is chronic consumption of a carbohydrate-rich diet with little or no protein.

Protein Turnover

The process of degrading or hydrolyzing proteins in the body.

Fatty Liver

A condition characterized by the accumulation of fat in the liver.

Alcohol Metabolism

The process by which the body breaks down and metabolizes alcohol.

Alcohol Dehydrogenase

An enzyme involved in the metabolism of alcohol.

Ketone Bodies

β-hydroxybutyrate, acetoacetate, and acetone, which are produced during ketogenesis and serve as alternative energy sources for the brain during fasting.

Ketosis

Elevated levels of ketone bodies in the bloodstream, often caused by fasting, exercise, or a high-fat diet.