Nutrition Flashcards
Photosynthesis
process by which autotrophs take in substances from the outside and convert them into stored forms of energy
6CO2 + 12H20 —> C6H12O6 + 6O2 + 6H20
Autotrophs
organisms which synthesize their own food with the help of solar energy from inorganic raw materials like CO2 and water.
Heterotroph
an organism that is unable to synthesize its own food, and therefore, has to rely on other sources, specifically plant and animal matter.
enzymes
bio catalysts that breaks down complex substances into simpler ones to be utilised by an organism
Carbohydrates which are not used immediately are stored in the form of
Starch
some of the energy derived from the food we eat is stored in our body in the form of
glycogen
3 steps of photosynthesis
- Absorption of light energy by chlorophyll
- Conversion of light energy into chemical energy + splitting of water molecules into O and H
- Reduction of CO2 into carbohydrates
Do all 3 steps of phsths happen immediately? Give an example
No
Desert plants absorb light energy during the day and use it to act upon CO2 taken up at night
How do stomatal pores open/close? Why?
It is controlled by guard cells
They swell when water flows: opening the pore and vice versa
The plant closes these pores when it does not need carbon dioxide for photosynthesis and to prevent excess loss of water
Compound that absorbs CO2
Potassium Hydroxide
Other raw materials plants need
nitrogen, phosphorus, iron and magnesium
Nitrogen is used by plants for? How is it acquired?
Compound and Protein synthesis
- Inorganic nitrates or nitrites
- Organic compounds fixed into soil by bacteria
Saprophytes
Feed on dead and decaying matter
Break-down the food material outside the body and then absorb it
Ex: mushroom, yeast, bread mould
Parasites
derive nutrition from plants or animals without killing them
ex cuscuta, ticks, lice, leech, tape worm
Amoeba nutrition
- takes in food using temporary finger-like extensions
- forms a food-vacuole
- complex substances are broken down into simpler ones which then diffuse into the cytoplasm
- undigested material is moved to the surface of the cell and thrown ou
Paramoecium
Food is moved to specific spot by the movement of cilia which cover the entire surface of the cell.
alimentary canal
tract from the mouth to the anus
Saliva
Salivary glands
Salivary amylase
Strach»_space; simple sugar
peristalsis
a series of rhythmic contractions that move food through the digestive tract
Stomach physical changes
Expands
Muscular walls churn food
Gastric glands
Pepsin: proteins
Mucus: protects inner lining of stomach
Hydrochloric acid: acidic medium for pepsin
Exit of food from the stomach is regulated by
Sphincter muscle
How does the length of small intestines vary
Herbivores eating grass need a longer small intestine to allow the cellulose to be digested
carnivores like tigers have a shorter small intestine
Liver
Bile juice
- makes chime alkaline
- emulsifies large fat globules
Pancreas
Pancreatic juice
Trypsin: proteins
Lipase: fats
Walls of small intestine
intestinal juice
proteins: amino acids
complex carbohydrates: glucose
fats: fatty acids and glycerol
