Phospholipids
Phospholipids are a kind of lipid that are well suited to both their biochemical and physiological function. They comprise of a glycerol backbone with a phosphate head and two fatty acid tails.
The tails are hydrophobic, meaning that they do not interact with water. When a group of phospholipids come into contact with water they arrange themselves in a bilayer that hides the hydrophobic parts from the aqueous surroundings.
This leaves the head of the phospholipid in contact with the aqueous surroundings. The heads are hydrophilic and can interact with water and other charged or polar substances on both sides of the bilayer.
The phospholipid bilayer acts as a barrier which allows cells to maintain internal conditions that are …show more content…
Describe the catabolic and anabolic fates of glucose. Provide detail of the metabolic pathways that underpin these fates and explain how their relative activity is regulated.
Glycolysis - glucose catabolism.
Glycolysis, part of cellular respiration, occurs in the cytosol of the cell and starts when the ATP level of the cell is low. It is the breakdown of glucose to pyruvic acid under aerobic conditions and to lactic acid under anaerobic conditions. It is a series of reactions and is the first step of most carbohydrate catabolism. Glycolysis breaks down glucose and forms pyruvate whilst initiating the production of two ATP molecules. The pyruvate product of glycolysis can be used in either anaerobic respiration when no oxygen is available or in aerobic respiration within the TCA cycle.
A glucose molecule is energized by a phosphate from ATP, forming glucose-6-phosphate. It is then altered to form fructose-6-phosphate.
Using a second ATP molecule a second phosphate is added to the fructose which becomes fructose-1,6-biophosphate.
This is then split into two 3-carbon molecules with one phosphate each. Two G3P molecules are then formed.
Both G3P molecules contribute two electrons and a hydrogen ion to NAD+ to form NAHD carrier
Phospholipids are a kind of lipid that are well suited to both their biochemical and physiological function. They comprise of a glycerol backbone with a phosphate head and two fatty acid tails.
The tails are hydrophobic, meaning that they do not interact with water. When a group of phospholipids come into contact with water they arrange themselves in a bilayer that hides the hydrophobic parts from the aqueous surroundings.
This leaves the head of the phospholipid in contact with the aqueous surroundings. The heads are hydrophilic and can interact with water and other charged or polar substances on both sides of the bilayer.
The phospholipid bilayer acts as a barrier which allows cells to maintain internal conditions that are …show more content…
Describe the catabolic and anabolic fates of glucose. Provide detail of the metabolic pathways that underpin these fates and explain how their relative activity is regulated.
Glycolysis - glucose catabolism.
Glycolysis, part of cellular respiration, occurs in the cytosol of the cell and starts when the ATP level of the cell is low. It is the breakdown of glucose to pyruvic acid under aerobic conditions and to lactic acid under anaerobic conditions. It is a series of reactions and is the first step of most carbohydrate catabolism. Glycolysis breaks down glucose and forms pyruvate whilst initiating the production of two ATP molecules. The pyruvate product of glycolysis can be used in either anaerobic respiration when no oxygen is available or in aerobic respiration within the TCA cycle.
A glucose molecule is energized by a phosphate from ATP, forming glucose-6-phosphate. It is then altered to form fructose-6-phosphate.
Using a second ATP molecule a second phosphate is added to the fructose which becomes fructose-1,6-biophosphate.
This is then split into two 3-carbon molecules with one phosphate each. Two G3P molecules are then formed.
Both G3P molecules contribute two electrons and a hydrogen ion to NAD+ to form NAHD carrier