nutrition in humans Flashcards
define nutrition
Nutrition is the process by which organisms obtain food and energy for growth, repair and maintenance of the body.
What are the processes in the human nutrition?
1) Ingestion
2) Digestion
3) Absorption
4) Egestion
5) Assimilation
What is ingestion?
It is when food is taken into the body
What is digestion?
when large food molecules are broken down into smaller, soluble molecules that can be absorbed by the body.
What is absorption?
when nutrients move from the intestines into the bloodstream
What is egestion?
when undigested matter is removed from the body
What is assimilation?
when nutrients are used by cells for maintenance of the body. For example, to provide energy or for making new cytoplasm for growth.
what does the human digestive system consist of?
It consists of the gut, or the alimentary canal, and the organs, liver, gall bladder, and pancreas associated with it.
define emulsification
It is the breaking up of fats into tiny fat droplets.
What are (emulsified) fats digested by?
They are digested by lipases into fatty acids and glycerol.
fats —(lipase)—> fatty acids + glycerol
What happens to the food in the mouth physically and chemically?
Physical digestion: teeth chew the food into smaller pieces
Chemical digestion:
Starch —(salivary amylase)—> maltose
what does Starch —(salivary amylase)—> maltose make?
It makes the sweetness appear after eating sweet foods
what is the purpose of physical digestion?
It increases the surface area-to-volume ratio to increase the efficiency of chemical digestion and releases nutrients from food during chewing.
What is the purpose of chemical digestion?
it breaks down insoluble food molecules into smaller soluble food molecules for easier absorption.
how does physical digestion happen?
It breaks down food mechanically. Large pieces of food -> smaller pieces of food. This exposes more surface area for enzymes to act on.
