Week 4 (EXAM 1) Flashcards

Question

Define proteins

Answer 1

Essential: Isoleucine (BCAA) Leucine (BCAA) Valine (BCAA) Non essential: Histamine Cysteine Tyrosine

Answer 2

”calories in vs calories out” Mathematic valuation of total calories consumed vs total calories expended

Answer 3

Low Energy Availability (LEA): LEA occurs when an individual’s dietary energy intake is insufficient to support the energy demands of exercise and normal physiological functions required for health. It is typically defined as the amount of energy available for bodily functions after accounting for the energy expended during exercise, expressed as: Energy Availability (EA) = (Energy Intake - Exercise Energy Expenditure) ÷ Fat-Free Mass (FFM) LEA is commonly associated with conditions such as the Female Athlete Triad and Relative Energy Deficiency in Sport (RED-S) and can lead to a variety of health and performance issues, including: * Menstrual dysfunction * Impaired bone health * Reduced metabolic rate * Poor immune function * Decreased muscle strength and endurance

Answer 4

RED-S is a syndrome caused by low energy availability (LEA) in athletes, where dietary energy intake is insufficient to meet the energy demands of exercise and basic physiological functions. While originally identified in female athletes as part of the Female Athlete Triad (energy deficiency, menstrual dysfunction, and low bone mineral density), RED-S is now recognized as a broader condition that affects both males and females. Risk factors: * Not eating enough calories to meet your energy needs * Exercising a lot without eating more to make up for the extra energy used * Playing sports that focus on weight or appearance * Following strict diets that cut out important foods or nutrients * Feeling pressure to stay thin or look a certain way for your sport

Answer 5

* First Law of Thermodynamics (conservation of Energy) o Energy cannot be created or destroyed – Energy transforms from one form to another but remains constant in total amount o Example: The body transforms energy from food into mechanical work, heat, and other forms of energy * Second Law of Thermodynamics (Entropy) o Energy transfer or transformation increases the entropy (disorder) of a system o Energy conversions are not 100% efficient; some energy is always lost as heat o Example During exercise, only a portion of chemical energy is used for movement the rest dissipates as heat * Third law of Thermodynamics (Absolute Zero) o As temperature approaches absolute zero, the entropy of a system approaches a constant minimum o Not directly applicable to biological systems under normal conditions

Answer 6

* Capable of generating large amounts of ATP * Generates ATP slowly * Aerobic respiration occurs within the mitochondria of the cell * Can utilize all 3 macronutrients as a fuel source

Answer 7

* Generates smaller, limited quantities of ATP * Creates ATP more rapidly * Anaerobic respiration takes place with the cell sarcoplasm * Can only utilize carbohydrates as a fuel source

Answer 8

Phosphagen system: * Cells store approximately 4 to 6 times more PCr than ATP * PCr reaches its maximum energy yield in about 10 s

Answer 9

1. Phase one can be thought of as the energy investment phase. 2. Phase two represents the energy generation phase.

Answer 10

Glycolysis begins with glucose being phosphorylated by hexokinase to form glucose-6-phosphate, trapping it inside the cell. It is then isomerized to fructose-6-phosphate and further phosphorylated by phosphofructokinase (PFK), the rate-limiting enzyme, to produce fructose-1,6-bisphosphate. This molecule is split by aldolase into two 3-carbon molecules: dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P). Only G3P proceeds directly through glycolysis. G3P is oxidized by glyceraldehyde-3-phosphate dehydrogenase, producing NADH and forming 1,3-bisphosphoglycerate. Substrate-level phosphorylation by phosphoglycerate kinase generates ATP, and further rearrangements lead to phosphoenolpyruvate (PEP) via enolase. Finally, pyruvate kinase catalyzes the conversion of PEP to pyruvate, producing another ATP.

Answer 11

Per glucose molecule, glycolysis produces a net gain of 2 ATP (4 ATP generated, 2 consumed), 2 NADH, and 2 pyruvate molecules. These products represent energy and intermediates that fuel further metabolic processes.

Answer 12

The fate of pyruvate depends on oxygen availability. Under aerobic conditions, pyruvate enters the mitochondria and is converted to Acetyl-CoA by pyruvate dehydrogenase, fueling the Krebs cycle for further ATP production. Under anaerobic conditions, pyruvate is converted to lactate by lactate dehydrogenase, regenerating NAD⁺ to allow glycolysis to continue.

Answer 13

Glycolysis is a fundamental metabolic pathway that provides energy quickly, especially during high-intensity activity or anaerobic conditions. It also supplies intermediates for other metabolic pathways and enables ATP production in cells lacking mitochondria, such as red blood cells. This pathway is critical for both energy and metabolic homeostasis.

Answer 14

(Lactic acid cycle) *Lactate produced as by product of anaerobic glycolysis. *Lactate taken to the liver where it is converted to pyruvate then to glucose. *Glucose returns to muscles to be metabolized to lactate.

Answer 15

(Kreb’s cycle) * The end product of glycolysis is the production of 2 pyruvate molecules that move through the sarcoplasm to enter the mitochondria, where they undergo further oxidation. * Movement into the Krebs cycle (KC) and electron transport chain (ETC) occurs in the presence of sufficient oxygen and when the rate of pyruvate production from glycolysis does not exceed the capacity for the mitochondria to receive pyruvate.

Answer 16

Products: 2 NADH 1 FADH 1 GTP/ATP

Answer 17

Preferred conversions: 1) carbs -> glucose -> glycogen 2) fats -> adipose tissue 3) protein -> amino acids

Answer 18

Beta-oxidation begins with the transport of fatty acids into the mitochondria using the carnitine shuttle system, where Carnitine Acyltransferase I (CAT1) converts fatty acyl-CoA to acyl-carnitine for entry, and CAT2 regenerates fatty acyl-CoA inside the mitochondria. The process then involves repeated cycles: oxidation by acyl-CoA dehydrogenase generates FADH₂, followed by hydration by enoyl hydratase to form L-β-hydroxyacyl-CoA. A second oxidation by acyl-CoA dehydrogenase produces NADH, and finally, cleavage by thiolase releases Acetyl-CoA and a shorter fatty acyl-CoA, which re-enters the cycle until the fatty acid is fully broken down.

Answer 19

A) 14 carbon fatty acid B) 1 cycle of beta oxidation: 1 Acetyl-CoA, 1 FADH, 1 NADH C) complete palmitate degradation: 8 Acetyl-CoA (to Kreb’s cycle) 7 NADH, 7 FADH (to ETC)

Answer 20

Beta-oxidation is a vital energy system during prolonged, low-intensity activities when carbohydrate stores are limited. It highlights the efficiency of fats as an energy source, providing a sustained ATP supply. This process is essential for endurance athletes and during fasting or starvation states.

Answer 21

yes, they all work but at different ratios depending on intensity and duration of an activity

Answer 22

A carbohydrate-deficient diet depletes muscle and liver glycogen and negatively affects performance in short-term anaerobic activity and prolonged intense aerobic activities

Answer 23

oxygen uptake

Answer 24

Regular aerobic exercise profoundly improves long- chain fatty acid oxidation, particularly TAG to active muscle in mild-to-moderate-intensity exercise

Week 4 (EXAM 1) Flashcards

(103 cards)