Sciences Flashcards
What are the main organic molecule classes in living organisms?
Carbohydrates, lipids, proteins, and nucleic acids.
What are the main nutrient types in human nutrition?
Carbohydrates, lipids, proteins, vitamins, minerals, water, fiber.
Hydrolysis
Large molecules are broken down to smaller ones by the addition of water
Condensation
Smaller molecules are built up into bigger ones by the removal of a water molecule
Carbohydrate classes:
Monosaccharides
The simplest carbohydrate
Ex: glucose, fructose, galactose
Disaccharides
Two monosaccharides joined together
Ex: sucrose, maltose, lactose
Polysaccharides
Several smaller monosaccharides
Ex: starch, cellulose, glycogen
monomer
a molecule that can be bonded to other identical molecules to form a polymer.
Polysaccharide:
Starch
Polymer of glucose
Made by plants
Stores energy
A branching molecule
Polysaccharide:
Glycogen
Polymer of glucose
Made by animals
Stores energy
A branching molecule
Polysaccharide:
Cellulose
Polymer of glucose
Made by plants, bacteria, algae ect
Provides structure & strength to plant cells/bodies
Main component of a plant cell wall (unbranched)
How are amino acids joined together to form proteins?
Two amino acids are joined by a covalent bond to form a dipeptide.
What are the characteristics of the condensation reaction?
Formation of a larger molecule
Elimination of water
Requires enzyme
Requires ATP
Forms bonds
Triglycerides: Saturated fatty acids
Regular cubic shape
Stack easily
Solid
Higher risk of deposits in arteries (stroke, heart attack, coronary heart disease)
Triglycerides: Unsaturated fatty acids
Irregular shape
Dont stack easily
Liquid
Lower risk of deposits in arteries
What are the 5 components (phases) of human nutrition?
Ingestion: Food intake into the body
Digestion: Breaking down large nutrient molecules into smaller ones
Absorption: Movement of small
nutrient molecules from the gut lumen to the blood.
Assimilation: Movement of nutrient molecules from the blood into body cells.
Egestion: Elimination of un-digested food and other materials (waste).
Associated organs
salivary glands - help digestion, oral hygiene, tase, protection and lubrication.
liver
gall bladder
pancreas - makes pancreatic juices called enzymes.
Mechanical digestion
Chewing, muscle contractions in stomach, peristalsis (muscle contractions that control the movement of the food through the digestive tract).
Chemical digestion
Catabolic (breaking down) reactions that break down large molecules into smaller ones.
STARCH chemical digestion
Starch + water —(amylase)–> maltose
Hydrolysis reaction
Occurs in the small intestine
Optimum pH = 7
Amylase is produced in the pancreas
STARCH chemical digestion PT2
Maltose + water —(maltase)–> individual glucose molecules
PROTEINS chemical digestion
Protein + water —(pepsin)–> smaller polypeptides
Hydrolysis reaction
Occurs in the stomach
Optimum pH = 2
PROTEINS chemical digestion PT2
Smaller polypeptides + water –(proteases)–> individual amino acids
What important substances does the pancreas produce and secrete?
Amylase, proteases, lipase, insulin, glucagon
Amylase function
Break down the bonds of starch molecules, transforming complex carbohydrates into simple sugars.
Proteases function
Breaking down bonds of protein smaller polypeptides into individual amino acids.
