Nutrition Flashcards
What is nutrition?
The process by which an organism obtains or produces food.
What are the two (2) types of nutrition? Explain them.
Autotrophic and heterotrophic nutrition. In autotrophic nutrition, organisms produce their own food while in heterotrophic nutrition organisms obtain ready made food from their environment.
State the three (3) types of heterotrophic nutrition and explain them.
Holozoic nutrition, saprophytic nutrition and parasitic nutrition. In holozoic nutrition, organisms obtain food by consuming other organisms, the ingested and then digested, in saprophytic nutrition, organisms called saprophytes obtain food by consuming the dead remains of other organisms which are absorbed outside the body and then absorbed, in parasitic nutrition organisms called parasites obtain food from the living body of an organism called the host which is usually harmed.
What is photosynthesis?
The process by which green plants use sunlight energy to convert carbon dioxide and water to glucose.
What is the formula for photosynthesis?
6CO2 + 6H2O —–> C6H12O6 + 6O2
What are the two (2) stages of photosynthesis? Explain them.
The light stage (light dependent stage) and the dark stage (light independent stage). In the light stage the light energy absorbed by chlorophyll in chloroplast is used to split the water molecules into hydrogen and oxygen atoms. In the dark stage the hydrogen atoms produced in the light stage are used to reduce the carbon dioxide molecules forming glucose.
What are the conditions required for photosynthesis to take place?
Carbon dioxide, water, sunlight, chlorophyll, enzymes and suitable temperature.
State two (2) mineral ions that are indirectly required for photosynthesis to take place.
Magnesium and iron (or nitrate).
The four (4) main factors which affect the rate of photosynthesis are ________ and they affect it because ________.
Water - affects the rate during dry seasons in tropical climates
Temperature - affects the rate during winter months in temperature climates
Carbon dioxide - affects the rate during the day
Light - affects the rate between dusk and dawn
State three (3) things that can happen to glucose after it is made (in plants).
Leaf cells can use it in respiration to produce energy
It can be converted to other organic substances by leaf cells
It can be condensed to starch and stored but can later be hydrolyzed back to glucose
What are the five (5) processes of heterotrophic nutrition in humans? Explain them.
Ingestion - the process by which food is taken into the body via the month
Digestion - the process by which food is broken down into simple soluble food molecules
Absorption - the process by which the soluble food molecules produced in digestion moves into the body fluids and cells
Assimilation - the process by which the body uses the soluble food molecules after digestion
Egestion - the process by which the undigested food material is removed from the body
