Introduction to Macronutrients and Glycolysis

These flashcards cover key concepts related to macronutrients, metabolic pathways, and the processes of glycolysis and energy production as discussed in the lecture.

Macronutrients

Nutrients required in large amounts for energy and growth, including carbohydrates, proteins, and fats.

Creatine Kinase

An enzyme that catalyzes the conversion of phosphocreatine to ATP, important in the phosphocreatine (PCR) system.

Negative Feedback

A regulatory mechanism where a change in a variable triggers a response that counteracts the initial change, important in maintaining homeostasis.

Anaerobic Glycolysis

A pathway that breaks down glucose or glycogen into pyruvate without the use of oxygen, producing a small amount of ATP.

Pyruvate

A key intermediate in several metabolic pathways; eventually converted into lactate in anaerobic conditions.

Lactate

A byproduct of anaerobic glycolysis; accumulation can cause muscle soreness due to pH changes.

Rate Limiting Enzyme

An enzyme that regulates the speed of a metabolic pathway, determining the overall rate of the reaction.

Phosphofructokinase (PFK)

A key regulatory enzyme in anaerobic glycolysis, controlling the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate.

ATP Yield of PCR System

The PCR system provides a yield of 1 ATP for each phosphocreatine broken down.

Energy Duration of ATP PCR System

The ATP PCR system can fuel high-intensity exercise for approximately 3 to 15 seconds.

Glycogenolysis

The breakdown of glycogen into glucose, primarily occurring in the liver.

Glucose 6 Phosphate (G6P)

The product of phosphorylating glucose, a key step in glycolysis that requires ATP.

NADH

Nicotinamide adenine dinucleotide (NAD) in its reduced form, produced during glycolysis and used in the electron transport chain.

ATP Cost of Glycolysis

The process of converting glucose into G6P costs 1 ATP in glycolysis.

ATP Net Gain in Glycolysis

The net gain of 2 ATP from glycolysis occurs after accounting for ATP spent and produced.

Hydrogen Ions

Ions produced during metabolic processes that can alter pH and contribute to muscle fatigue.

Cytoplasm

The part of the cell outside the mitochondria where glycolysis occurs.

Enzyme Activity

The rate at which an enzyme catalyzes a reaction, influenced by substrate availability and other factors.

Energy Source During Exercise

During initial exercise, the body primarily uses ATP from PCR, followed by anaerobic glycolysis as demand increases.

Transition Between Energy Systems

The body transitions from PCR to anaerobic glycolysis and eventually to aerobic systems as exercise duration increases.

Glucose vs Glycogen in Glycolysis

Using glucose yields 2 ATP, while using glycogen yields 3 ATP due to differing ATP costs.