sports science - option d(1)

1.1: Outline the features of the principal components of the digestive system

Mouth, Esophagus, Stomach, Small intestine, Large intestine, Pancreas, Liver, Gall bladder

Features of the mouth

• Mechancial and chemical digestion (carbohydrates)

• Salivary amylase

• pH7

Features of esophagus

• Peristalsis/peristaltic (involuntary muscle movement)

Features of the stomach

• Rugae/lumen/mucous coating

Features of small intestine

• Villi/microvilli (tiny little folds that sit within small intestine and can increase surface area and absorption of nutrients

Features of large intestine

• Water balance/vitamin absorption

Features of pancreas

• Production of enzymes

• Pancreatic lipase/amylase/trypsin

Features of liver

• Production of bile

Features of gall bladder

• Storage of bile

1.2: State the typical pH values found throughout the digestive system (include location)

• Mouth: 5.5 to 7.5

• Stomach: 1.0 to less than 4.0

• Small intestine: 6.0 to 8.0

BG Knowledge: Enzyme

Enzymes are proteins that act as biological catalysts by accelerating chemical reactions in our bodies

1.3: Describe the function of enzymes in the context of macronutrient digestion

Enzymes act as a biological catalyst, accelerating the rate that large molecules of food are broken down into smaller molecules (in order to facilitate their absorption by the body)

Reference macronutrient digestion

Each macronutrient (carbs, proteins, fats) requires a specialised enzyme to be broken down

• this process involves a lock and key model

BG Knowledge: Digestive Enzymes

• Enzymes in the alimentary canal that break down food so that that the organism can absorb it

1.4: Explain the need for enzymes in digestion

• Aid in the breakdown of large molecules into smaller molecules to more soluble substances that get absorbed into the bloodstream

• Increase the rate of digestion without disrupting body temperature (increase up to 37 degrees and then slows down)

• Most enzymes only catalyse one specific reaction, making them specialised.

1.5: List the enzymes that are responsible for the digestion of carbohydrates, fats and proteins from the mouth to the small intestine - Carbohydrates

Carbs

Enzyme: Salivary amylsae, pancreatic amylase

Site: Oral cavity, small intestine

1.5: List the enzymes that are responsible for the digestion of carbohydrates, fats and proteins from the mouth to the small intestine - Fats

Fats

Enzyme: Pancreatic lipase, bile

Site: Small intestine

1.5: List the enzymes that are responsible for the digestion of carbohydrates, fats and proteins from the mouth to the small intestine - Proteins

Proteins

Enzymes: Pepsin, trypsin

Site: Stomach, small intestine

1.6: Describe the absorption of glucose, amino acids and fatty acids from the intestinal lumen to the capillary network - Glucose

• Carbohydrates are absorbed as monosaccharides

• Occurs via active transport where Glucose is transported into epithelial cells of villi

• Glucose crosses the brush-border membrane and passes through the cytosol of the absorptive cell, crossing the basolateral membrane

• Then enters capillary network

1.6: Describe the absorption of glucose, amino acids and fatty acids from the intestinal lumen to the capillary network - Amino Acids

• Amino acids cross the brush-border membrane of intestinal cells

• Pass through cytosol of absorptive cell and crosses basolateral membrane

• Enter the capillary network that surrounds the intestine

1.6: Describe the absorption of glucose, amino acids and fatty acids from the intestinal lumen to the capillary network - Fatty Acids

• Brush border found on the villi in the small intestine

• Brush border creates a very large surface area for quicker absorption of fatty acids