Carbohydrate Metabolism Basics

GluT4 facilitates glucose entry into muscle cells and adipocytes, and is regulated by insulin which promotes its translocation to the cell membrane.

GluT2 is an insulin-independent transporter found in liver cells.

Under anaerobic conditions, glycolysis produces lactate and 2 ATP molecules.

<p>Gluconeogenesis is crucial during fasting as it provides a continuous supply of glucose to organs like the brain and red blood cells.</p> Signup and view all the answers

<p>The main precursors of gluconeogenesis are lactate, amino acids, and glycerol.</p> Signup and view all the answers

<p>Phosphofructokinase catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate.</p> Signup and view all the answers

<p>The net ATP yield from glycolysis is 2 ATP per molecule of glucose.</p> Signup and view all the answers

<p>Glycolysis is significant in red blood cells as it is the only energy pathway available, providing necessary ATP.</p> Signup and view all the answers

<p>The primary outcome is the oxidation of carbohydrates, amino acids, and fatty acids into carbon dioxide and water while producing ATP, NADH, and FADH2.</p> Signup and view all the answers

<p>Pyruvate is oxidatively decarboxylated to Acetyl CoA by the pyruvate dehydrogenase complex.</p> Signup and view all the answers

<p>Each Acetyl CoA produces 12 ATP molecules: 3 NADH (9 ATP), 1 FADH2 (2 ATP), and 1 GTP (1 ATP).</p> Signup and view all the answers

<p>The cycle provides intermediates for the biosynthesis of amino acids, fatty acids, and porphyrins.</p> Signup and view all the answers

<p>In the well-fed state, glucose is converted to glycogen and fat, while in the fasting state, fatty acids are converted into ketone bodies and glucose is produced through gluconeogenesis.</p> Signup and view all the answers

<p>The liver synthesizes glucose through gluconeogenesis and produces ketone bodies from fatty acids to provide energy.</p> Signup and view all the answers

<p>Glucose absorption involves transporters GluT1/GluT4 for intestinal uptake and GluT2 for transport into the bloodstream.</p> Signup and view all the answers

<p>During fasting, the liver breaks down fatty acids into ketone bodies and undergoes gluconeogenesis to supply glucose.</p> Signup and view all the answers

Pyruvate, a product of glycolysis, is converted into Acetyl-CoA under aerobic conditions by the pyruvate dehydrogenase complex. This is the crucial step for the citric acid cycle.

The citric acid cycle, also known as the Krebs cycle, generates 12 ATP molecules per Acetyl-CoA molecule.

The citric acid cycle provides intermediates for the biosynthesis of essential molecules like amino acids, fatty acids, and porphyrins.

In a well-fed state, the body prioritizes storing excess energy. Glucose is converted to glycogen in the liver and fat in adipose tissue, while fatty acids are stored in adipose tissue.

During fasting, the body utilizes fat stores to create energy. Fatty acids are broken down to produce ketone bodies and the liver produces glucose through gluconeogenesis.

The liver plays a vital role in maintaining glucose homeostasis during fasting by producing glucose through gluconeogenesis and ketone bodies from fatty acids.

A glucose transporter that facilitates glucose entry into muscle cells and fat cells. Its activity is increased by insulin, which promotes its movement to the cell membrane.

GluT1 and GluT4 facilitate glucose uptake from the intestines, while GluT2 transports glucose into the bloodstream for distribution.

Excess glucose in the well-fed state is converted to fatty acids and stored in adipose tissue. Meanwhile, glucose is metabolized into glycogen for short-term energy storage in the liver.

This glucose transporter is independent of insulin. It is found in liver cells and helps take up glucose regardless of insulin levels.

The metabolic pathway that breaks down glucose into pyruvate (aerobic conditions) or lactate (anaerobic conditions) with the production of energy. It's central to energy production in many cells.

These enzymes regulate key steps in glycolysis, ensuring efficient glucose breakdown and energy production. They control the flow of the pathway based on cell needs.

Pyruvate is produced under aerobic (oxygen present) conditions, while lactate is created under anaerobic (oxygen absent) conditions. They are the end products of glucose breakdown.

The process of creating glucose from non-carbohydrate sources such as lactate, amino acids, and glycerol. It's essential for maintaining blood glucose levels during fasting or starvation.

Lactate is produced during anaerobic glycolysis in muscles and is transported to the liver to be converted back into glucose through gluconeogenesis. It's a key link between muscle activity and glucose production.

The citric acid cycle, also known as the Krebs cycle, is a central metabolic pathway responsible for generating energy (ATP) through the oxidation of acetyl-CoA, which is derived from carbohydrates, fats, and proteins.