Chapter 5 Flashcards
Examples of autotrophs
Plants, algae and some bacteria.
Autotrophs
Are ale to make their own organic material from simple inorganic substances typically using the energy of sunlight.
What is food for heterotrophs
Any organic matter that it can obtain, break down and use ad a source of energy and organic matter.
Definition of heterotrophs
An organism that cannot make its own food and must ingest or absorb organic material from its environment
Examples of heterotrophs
All animals, all fungi and some bacteria
Photosynthesis
Is the process of converting the energy of sunlight to a chemical energy in sugars
What are the products and raw materials of photosynthesis
Products: glucose and oxygen gas
Materials: water and carbon dioxide
Where does photosynthesis occur?
In the chloroplasts
Purpose of digestion
To break down food into simple water soluble molecules that are small enough to be moved across the plasma membrane of cells
Mechanical digestion
The physical breakdown of food into smaller pieces by chewing or muscle movement in the stomach
Advantage of mechanical digestion
This increases the surface area of the food, to speed up the rate at which the enzymes can work in chemical digestion
Example of mechanical digestion
A piece of meat is still meat, only in small pieces.
Chemical digestion
Enzymes break complex molecules into their simplest forms, the molecules are chemical changed.
Process of chemical/ what happens to the meat
The meat is no longer meat, it has been broken down into glucose, amino acids, triglycerides and fatty acids,
Phases of digestion
Ingestion, digestion, absorption, egestion
Ingestion
Taken in mouth
Mechanical: teeth
Chemical: amylase (saliva) break down starch
- taking nutrients in
Digestion
Breaking down complex molecules into simpler ones by mechanical and chemical processes
- tongue pushes food into the oesophagus
- the epiglottis (small flap of tissue) closes off the teacher, preventing food from entering the respiratory tract
- muscular contractions (peristalsis) push food down into the stomach
Abosorption
Most absorbed through small intestines
Taking up digested molecules into cells of the digestive tract
Egestion
Removal f wastes from body, left with what we cannot divest. Go straight through body without entering bloodstream.
Eg. Fibre cannot digest but are useful to digestive system
Mouth cavity
- entry for food- ingestion
- in upper and lower jaws, teeth go grasp, tear or chew food.
- tongue may help to catch or manipulate food