Nutrition and ENergy Flashcards
Role of the Digestive tract
Convert ingredients into nutrients and energy necessary for survival
Four parts of digestion
GI tract
Digestive juices
Enzymes Hormones nerves and blood
Mesentery
State areas of secretions Digestion (mechanical and chemical digestion)
Mouth/ stomach/ small intestine/ Large intestine
Site of most Absorption
small intestine
Key components of Nutrients
Carbs
Protein
Fat
Non yielding nutients
Vitamins and Minerals
Carb sources
Grains, fruits, milk, yogurt, sweet potatoes, Legumes
State the two types of Simple Carbs
Monosaccharides/ Disaccharides
Monosaccharides structure
one sugar unit same no. of atoms but different arrangement= different sweetness
Disaccharides
two sugar units
Monosaccharides structure
Same number of atoms but different arrangement which gives them different levels of sweetness.
Disaccharides
Carbs are put together by condensation reaction and broken apart by hydrolysis reactions
2 glucose units
Complex carbs examples
Starch, Fibre, Glycogen
Complex carbs are examples of?
polysaccharides
many glucose units
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What occurs in the mouth
Mechanical digestion: mouth teeth tongue
Chemical digestion:
Saliva, salivary glands secretes amylase
Action of Saliva on starch
Amylase secreted in the mouth cuts the long chains of glucose to 1, 2, 3 glucose molecules
Action of Stomach on Carbs
The main role of the stomach is to mix the content around and push the starch towards the small intestine
- no starch digestion occurs in the stomach
Stomachs relationship with dietry fibre
not digested in the stomach, but delays gastric emptying
Small intestines roll in starch (carb) digestion
most starch digestion occurs here. When starch reaches small intestine the pancreas is stimulated and secretes pancreatic amylase via the pancreatic duct.
What does Pancreatic amylase do
Breaks down the starch molecule down further by breaking the linear chain
what are the small intestines Enterocyte involvement in digestion
Enterocyte break down starch. they break disaccharides into smaller fragments (monosaccharides that can be absorbed across the intestinal cells
Describe how glucose is transported in the small intestine
Glucose is transported inside the intestinal cell by transporter
- Glucose transported into the bloodstream by facilitated diffusion (no ATP needed)
Large intestines rolls in digestion
resistant starch reaches the large intestine undergoes fermentation by gut bacteria= short chain of fatty acids.
Large intestines roll with Dietary fibre
passes through small intestine and reaches the large intestine and colon
What is Lactose malabsorption
inability to digest lactose in the small intestine
Describe undigested lactose in the small intestine
lactose remains in the small intestine, moves to the large intestine- fermentation due to gut bacteria. attracts water, increase in pain and produces gas
-diarrhea/ gas irritated GI tract
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