Nutrition in Active Life and Metabolism Practice Questions

Comprehensive vocabulary flashcards covering Vitamin D, metabolism of amino acids, carbohydrates, lipids, proteins, and essential minerals (Iron, Potassium, Selenium, Calcium, Zinc, Magnesium) and metabolic pathways like the Krebs cycle and Beta-oxidation based on the provided lecture questionnaires.

Vitamin D

A liposoluble compound that acts as both a vitamin and a regulatory hormone for mineral metabolism.

Vitamin D (Muscle Function)

Promotes the absorption and availability of calcium necessary for muscle contraction and stimulates muscle protein synthesis by binding to $VDR$ receptors.

Deamination

The metabolic process of removing an amino group from an amino acid, often used as an alternative energy source during prolonged exercise.

Glutamate

The principal receiver and donor of amino groups in nitrogen metabolism during exercise.

Glutamate Dehydrogenase Products

The substances generated by the oxidative deamination of glutamate: \text{\alpha-cetoglutarato} and ammonium.

Pyridoxal Phosphate ($\text{Vitamin B6}$)

The fundamental cofactor required for transamination reactions in amino acid metabolism.

Glucose-Alanine Cycle

A process where alanine formed in the muscle is transported to the liver to be used in the production of glucose.

$$GLUT5$$

The intestinal transporter responsible for the absorption of fructose via facilitated diffusion, independent of sodium and $ATP$.

Carbohydrate Digestion (Start)

Begins in the mouth through the action of the enzyme salivary amilase.

Sedoheptulose

A 7-carbon monosaccharide (heptose) that serves as an intermediate in the pentose phosphate pathway.

Non-digestible Carbohydrates

A group of carbohydrates including cellulose, hemicellulose, and pectins that cannot be digested by human enzymes.

Iron

An essential mineral participating in oxygen transport and various metabolic processes.

Hepcidin

A hormone that increases after high-intensity training and reduces the availability of iron for the organism.

Iron Absorption Window

The period between $0$ and $60\text{ minutes}$ post-exercise when the greatest absorption of iron occurs.

Potassium ($K^+$)

The primary cation of the intracellular space.

Sodium-Potassium $ATP$ase

A pump in the muscle fiber that expels three sodium ions and introduces two potassium ions to maintain the resting membrane potential.

Potassium (Action Potential)

Participates in the repolarization of the membrane by exiting the cell.

Lipids

Hydrophobic biomolecules with important structural and energetic functions.

Bile

A substance that emulsifies fats to facilitate their digestion and absorption in the duodenum.

Structural Lipids

Phospholipids and cholesterol, which are key components of cell membrane structure.

Protein Recommendation (Strength Athletes)

A daily intake of $1.6\text{--}2.2\text{ g/kg/day}$ for athletes focused on strength and muscular hypertrophy.

Secondary Protein Structure

Plegamientos locales such as the \text{\alpha-h\'elice} and \text{l\'amina \beta}, stabilized by hydrogen bonds.

Essential Amino Acids

Amino acids that the organism cannot synthesize and must be obtained through the diet, such as tryptophan, lysine, and methionine.

Selenium

A micronutrient that contributes to immune-endocrine function and provides cellular antioxidant protection.

Yodotironina Desyodasa

A selenoprotein enzyme responsible for activating thyroid hormones for cellular metabolism.

Krebs Cycle

A mitochondrial process that oxidizes Acetyl-CoA to form reduced coenzymes ($NADH$ and $FADH_2$) for the respiratory chain.

Citrate Sintasa

The enzyme that catalyzes the formation of citrate from Acetyl-CoA and oxalacetate to initiate the Krebs cycle.

Calcium (Muscle Contraction)

Binds to troponin C to displace tropomyosin and expose actin-myosin binding sites.

Calcitonin

A hormone released by thyroid C cells in response to high serum calcium to reduce bone resorption.

Zinc ($Zn$)

A mineral acting as a catalytic cofactor for antioxidant enzymes ($\text{super\'oxido dismutasa}$) and pH regulators ($\text{anhidrasa carb\'onica}$).

Phytates

Compounds found in cereals and legumes that limit the absorption of zinc in the duodenum and jejunum.

Vitamin B12

A $\text{B-complex}$ vitamin indispensable for DNA synthesis and erythrocyte maturation; deficiency causes megaloblastic anemia.

$$GLUT4$$

An insulin-dependent glucose transporter found mainly in skeletal muscle and adipose tissue.

Glucagon

A hormone that stimulates gluconeogenesis and glycogenolysis in the liver during fasting between training sessions.

Glycolytic System

A metabolic pathway occurring in the cytosol that produces $ATP$ rapidly from glucose or muscle glycogen.

$$\beta\text{-Oxidation}$$

The mitochondrial degradation of activated fatty acids into sequential units of Acetyl-CoA.

Carnitine

An amino-acid-derived molecule that serves as the indispensable transporter for long-chain fatty acids ($\text{acil-CoA}$) into the mitochondrial matrix.

$$FatMax$$

The relative exercise intensity (low to moderate, approx. $\le 65\text{--}70\%\text{ of } VO_2max$) at which the absolute rate of fat oxidation is maximized.