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Flashcards in Nutrition Deck (88)
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What is autotrophic nutrition?

Simple inorganic molecules built up into complex organic molecules


What is photoautrophic nutrition?

Organisms that use light energy to convert simple inorganic molecules into complex organic ones.
.Chlorophyll is used to absorb sunlight energy


What is an example of an organism that uses photoautrophic nutrition?

Green plants, such as Dandelion, Algae and certain bacteria


What is chemoautrophic nutrition?

.Use the energy derived from special methods of respiration (such as the oxidation of hydrogen sulphide/ sulphur/ ferrous ions or nitrates) to convert simple inorganic molecules into complex organic ones.


What is an example of an organism that uses chemoautotrophic nutrition?

Bacteria eg nitrosomonas


Define heterotrophic nutrition?

Complex organic molecules broken down to release energy (consumers)


How does digestion work in holozoic feeders ?

Food is processed as it passes along the gut


How does the structure of the gut differ between simple organisms that eat one type of food and more complex organisms?

Simple organisms have a undifferentiated gut, where as advanced organisms with a varied diet have a divided gut


Why are complex organisms gut divided?

Allows for specialisation for specific functions like, ingestion, digestion, adsorption and egestion.


What do saprotrophs/ saprobionts feed on?

Dead or decaying matter


What organisms are classed as saprotrophs/ saprobionts?

All fungi and some bacteria


What type of digestion do saprotrophs/ saprobionts carry out?



What is extracellular digestion?

When enzymes are secreted onto food outside the body then soluble products of digestion are adsorbed by diffusion across the cell membrane.


Describe the process of fungal feeding?

1.Fungi secrete enzymes from the growing tip of the hyphae which penetrates the food to secrete the enzymes.
2. The enzymes diffuses out through the cell membrane and cell wall onto the surface of the food (Substrate)
3.These enzymes digest the food into soluble products
4.These soluble products are the absorbed into the hyphae through the cell wall and cell membrane by facilitated diffusion or active transport.
5. The soluble products are transported within the fungi and excess are stored
6. This is extracellular digestion


What is a parasite?

An organism that feeds on or in another organisms (host)


Where do parasites live?

On or in the host


What happens to the host of a parasite?

Harm or death


What is the case study example for parasites?



What is mutalism?

Also known as symbiosis and involves a close association between members of two different species.

(When two different species rely on each other for survival)


Why do different parts of the human gut have different pH values?

Different enzymes have different optimum pH


What type of feeder is amoeba?

Amoeba which are protocista are holozoic feeders


Describe the structure of amoeba?

They are a single celled organisms with a large surface area to volume ratio


How do amoeba obtain their nutrition?

They obtain their nutrients by diffusion, facilitated diffusion or active transport across their cell surface membrane


How do amoeba take in larger molecules?

By endocytosis, which in turn fuse with lysosomes so that the contents can be digested


What happens to the products of digestion in amoeba?

The products of digestion are absorbed into the cytoplasm and ingestible material is egested by exocytosis.


What is ingestion?

Large food particles are taken into the buccal cavity


What is Mechanical Digestion?

The action of teeth, saliva and the tongue (mastication) so it may then move into the gut


What is chemical digestion?

The chemical breakdown (enzymes) of large insoluble molecules to small, soluble molecules. (Different regions of the gut have different pH therefore the enzymes found in the different regions have different pH optima)


What is absorption?

Small, soluble food molecules move from the small intestine into the blood stream.


What is the serosa and what is its function?

Tough connective tissue covered by squamous epithelium that protects the wall of the gut and reduces friction from other organs in the abdomen as the gut moves during the digestive process.