Respiration, sugars carbohydrates Flashcards
What is respiration?
Respiration is the process by which cells break down food molecules (such as glucose) to release energy.
What is the fate of pyruvate under anaerobic conditions?
Under anaerobic conditions, pyruvate undergoes fermentation to produce ethanol or lactate and regenerate NAD+.
What happens during glycolysis?
Glucose (6C) is broken down into two molecules of pyruvate (3C), producing a net gain of 2 ATP and 2 NADH.
What is the main function of the TCA cycle?
The TCA cycle (Krebs cycle) oxidizes Acetyl-CoA to produce NADH, FADH2, GTP (ATP), and CO2.
What happens to pyruvate under aerobic conditions?
Pyruvate is converted into Acetyl-CoA in the mitochondria through decarboxylation by the pyruvate dehydrogenase complex.
What is the energy yield from one turn of the TCA cycle?
One turn of the TCA cycle produces 3 NADH, 1 FADH2, 1 GTP (ATP), and releases 2 CO2 molecules.
How does ATP synthase work in the electron transport chain?
ATP synthase uses the proton gradient created by the ETC to generate ATP from ADP and Pi.
What is the net ATP yield from the complete breakdown of one glucose molecule?
The complete breakdown of one glucose molecule through glycolysis, the TCA cycle, and oxidative phosphorylation yields about 30 ATP.
What happens in the electron transport chain?
NADH and FADH2 donate electrons to the electron transport chain, leading to the formation of a proton gradient across the mitochondrial membrane and the synthesis of ATP via oxidative phosphorylation
How is glycolysis regulated?
Glycolysis is controlled at three key steps: hexokinase, phosphofructokinase, and pyruvate kinase, which are regulated by feedback mechanisms like ATP and citrate levels.
What is glycogen and where is it stored?
Glycogen is a highly branched polymer of glucose, stored in the liver and muscles as an energy reserve.
What causes lactose intolerance?
Lactose intolerance occurs due to a deficiency of the enzyme lactase, which breaks down lactose into glucose and galactose.
What is gluconeogenesis?
Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate precursors like lactate, pyruvate, glycerol, and some amino acids.
How is the TCA cycle regulated?
The TCA cycle is regulated by enzymes such as pyruvate dehydrogenase (inhibited by ATP, NADH) and isocitrate dehydrogenase (activated by ADP, inhibited by NADH, ATP)
What is maltose?
Maltose is a disaccharide made of two glucose molecules joined by an α(1→4) bond, commonly found as a breakdown product of starch.
