Metabolism and Nutrients Study Guide

Metabolism

All chemical reactions within the body essential for maintaining life.

Catabolism

Breaking down molecules to release energy (e.g., glucose breakdown during cellular respiration).

Anabolism

Building larger molecules from smaller ones (e.g., protein synthesis from amino acids).

ATP (Adenosine Triphosphate)

The primary energy carrier in cells.

High-energy phosphate bonds

Energy is stored in these and released when ATP is converted to ADP.

Glycolysis

Occurs in the cytoplasm; glucose is broken down into pyruvate, yielding 2 ATP.

Krebs Cycle (Citric Acid Cycle)

Occurs in mitochondria; processes pyruvate and generates electron carriers (NADH, FADH2).

Electron Transport Chain

Occurs in the mitochondrial membrane; produces approximately 32 ATP using oxygen.

Lipolysis

Breakdown of triglycerides into glycerol and fatty acids.

Beta-oxidation

Breaks down fatty acids in the mitochondria to generate acetyl-CoA for the Krebs cycle.

Lipogenesis

Synthesis of fat from excess glucose or amino acids.

Deamination

Amino group removed from amino acids.

Proteins (Excess)

Can be converted into glucose or fat if in excess.

Carbohydrates

Primary energy source; stored as glycogen in the liver and muscles.

Proteins

Used for building tissues, enzymes, and hormones; can be used for energy.

Lipids

Energy storage, insulation, and hormone synthesis.

Vitamins

Organic compounds that help enzymes function as coenzymes.

Fat-soluble Vitamins

A, D, E, K

Water-soluble Vitamins

B-complex, C

Minerals

Inorganic nutrients needed for various body functions (e.g., calcium for bones, iron for hemoglobin).

Water

Essential for temperature regulation, chemical reactions, and the transport of substances.

Insulin

Lowers blood glucose by promoting glucose uptake and storage.

Glucagon

Raises blood glucose by promoting glycogen breakdown and gluconeogenesis.

Thyroid hormones

Increase basal metabolic rate.

Carbohydrates

Broken down into monosaccharides (mainly glucose). Digestion begins in the mouth, absorption in the small intestine.

Proteins

Broken down into amino acids. Digestion begins in the stomach, absorption in the small intestine.

Lipids

Broken down into fatty acids and monoglycerides. Emulsified by bile, absorbed in the small intestine into lymphatic vessels.

Fat-soluble vitamins (A, D, E, K)

Vitamins absorbed with dietary fats and stored in body fat.

Water-soluble vitamins (B-complex, C)

Vitamins absorbed directly into the bloodstream in the small intestine.

Major minerals (e.g., calcium, sodium, potassium)

Absorbed in the small intestine; enhanced by vitamin D.

Trace minerals (e.g., iron, zinc, iodine)

Absorbed in the small intestine in smaller quantities.

What does metabolism encompass?

Encompasses all chemical reactions within the body essential for maintaining life.

What is catabolism?

Breaking down molecules to release energy (e.g., glucose breakdown during cellular respiration).

What is anabolism?

Building larger molecules from smaller ones (e.g., protein synthesis from amino acids).

What is ATP (Adenosine Triphosphate)?

The primary energy carrier in cells.

How is energy stored and released in ATP?

Energy stored in high-energy phosphate bonds is released when ATP is converted to ADP.

What is glycolysis?

Occurs in the cytoplasm; glucose is broken down into pyruvate, yielding 2 ATP.

What is the Krebs Cycle (Citric Acid Cycle)?

Occurs in mitochondria; processes pyruvate and generates electron carriers (NADH, FADH2).

What is the Electron Transport Chain?

Occurs in the mitochondrial membrane; produces approximately 32 ATP using oxygen.

What is lipolysis?

Breakdown of triglycerides into glycerol and fatty acids.

What is Beta-oxidation?

Breaks down fatty acids in the mitochondria to generate acetyl-CoA for the Krebs cycle.

What is lipogenesis?

Synthesis of fat from excess glucose or amino acids.

What is deamination?

Amino group removed from amino acids.

What happens to excess proteins?

Can be converted into glucose or fat if in excess.

What are carbohydrates?

Primary energy source; stored as glycogen in the liver and muscles.

What are proteins used for?

Used for building tissues, enzymes, and hormones; can be used for energy.

What is the function of lipids?

Energy storage, insulation, and hormone synthesis.

What are vitamins?

Organic compounds that help enzymes function as coenzymes.

What are fat-soluble vitamins?

A, D, E, K

What are water-soluble vitamins?

B-complex, C

What are minerals?

Inorganic nutrients needed for various body functions (e.g., calcium for bones, iron for hemoglobin).

Why is water essential?

Essential for temperature regulation, chemical reactions, and the transport of substances.

What is the role of insulin?

Lowers blood glucose by promoting glucose uptake and storage.

What is the role of glucagon?

Raises blood glucose by promoting glycogen breakdown and gluconeogenesis.

What is the function of thyroid hormones?

Increase basal metabolic rate.

How are carbohydrates digested and absorbed?

Broken down into monosaccharides (mainly glucose). Digestion begins in the mouth, absorption in the small intestine.

How are proteins digested and absorbed?

Broken down into amino acids. Digestion begins in the stomach, absorption in the small intestine.

How are lipids digested and absorbed?

Broken down into fatty acids and monoglycerides. Emulsified by bile, absorbed in the small intestine into lymphatic vessels.

How are fat-soluble vitamins absorbed?

Vitamins absorbed with dietary fats and stored in body fat.

How are water-soluble vitamins absorbed?

Vitamins absorbed directly into the bloodstream in the small intestine.

How are major minerals absorbed?

Absorbed in the small intestine; enhanced by vitamin D.

How are trace minerals absorbed?

Absorbed in the small intestine in smaller quantities.

Bile salts

Emulsifies lipids in the small intestine.

Pancreatic lipase

Breaks triglycerides into absorbable units.

Micelles and chylomicrons

Transport lipids into lymphatic vessels.

Salivary amylase

Begins the digestion of carbohydrates in the mouth.

Pancreatic amylase

Continues carbohydrate digestion in the small intestine.

Begins protein digestion

Metabolism

All chemical reactions within the body essential for maintaining life.

Catabolism

Breaking down molecules to release energy (e.g., glucose breakdown during cellular respiration).

Anabolism

Building larger molecules from smaller ones (e.g., protein synthesis from amino acids).

ATP

Adenosine triphosphate; the primary energy carrier in cells.

Glycolysis

Occurs in the cytoplasm; glucose is broken down into pyruvate, yielding 2 ATP.

Krebs Cycle (Citric Acid Cycle)

Occurs in mitochondria; processes pyruvate and generates electron carriers (NADH, FADH2).

Electron Transport Chain

Occurs in the mitochondrial membrane; produces approximately 32 ATP using oxygen.

Lipolysis

Breakdown of triglycerides into glycerol and fatty acids.

Beta-oxidation

Breaks down fatty acids in the mitochondria to generate acetyl-CoA for the Krebs cycle.

Lipogenesis

Synthesis of fat from excess glucose or amino acids.

Protein Metabolism

Amino acids are deaminated (amino group removed), and the remaining carbon skeleton enters the Krebs cycle.

Carbohydrates

Primary energy source; stored as glycogen in the liver and muscles.

Proteins

Used for building tissues, enzymes, and hormones; can be used for energy.

Lipids

Energy storage, insulation, and hormone synthesis.

Vitamins

Organic compounds that help enzymes function as coenzymes.

Fat-soluble Vitamins

A, D, E, K

Water-soluble Vitamins

B-complex, C

Minerals

Inorganic nutrients needed for various body functions (e.g., calcium for bones, iron for hemoglobin).

Water

Essential for temperature regulation, chemical reactions, and the transport of substances.

Insulin

Lowers blood glucose by promoting glucose uptake and storage.

Glucagon

Raises blood glucose by promoting glycogen breakdown and gluconeogenesis.

Thyroid hormones

Increase basal metabolic rate.

Macronutrients

Carbohydrates, proteins, and lipids required in large amounts for energy and body functions.

Monosaccharides

Building blocks of carbohydrates, mainly glucose.

Salivary amylase

Enzyme that begins carbohydrate digestion in the mouth.

Pancreatic amylase

Enzyme that continues carbohydrate digestion in the small intestine.

Absorption of Monosaccharides

Occurs in the small intestine (mostly jejunum) via active transport into blood capillaries.

Amino acids

Building blocks of proteins.

Pepsin

Enzyme that begins protein digestion in the stomach.

Pancreatic proteases

Enzymes (trypsin, chymotrypsin) that continue protein digestion in the small intestine.

Absorption of Amino Acids

Occurs in the small intestine (duodenum and jejunum) via active transport into blood.

Fatty acids and monoglycerides

Products of lipid breakdown.