EMPA Flashcards
(29 cards)
What is the function of the Leaf palisade cell?
To carry out photosynthesis.
Explain the three features which make the Leaf Palisade Cell suited to its function…
1) Long thin cells- form a continuous layer to absorb sunlight.
2) Numerous chloroplasts- arranged in positions to absorb max sunlight.
3) Large vacuole- pushes cytoplasm+chloroplasts to edge of cell.
Describe the Chloroplast envelope…
It is a double plasma membrane that surrounds the organelle. It is highly selective as to what it lets in and out of the chloroplast.
What is the grana? (Chloroplasts)
The grana are stacks up to 100 disc like structures called Thylakoids.
What do Thylakoids contain?
Thylakoids contain chlorophyll.
What is chlorophyll?
The photosynthetic pigment found in Thylakoids in the chloroplasts.
Where does the first stage of photosynthesis occur?
The grana in the chloroplasts.
What is the stroma? (chloroplasts)
The stroma is a fluid filled matrix.
Where in the chloroplasts does the second stage of photosynthesis occur?
In the stroma
Explain the three features which make chloroplasts adapted to their function of harvesting sunlight and carrying out photosynthesis…
1) Granal membranes- provide large SA for the attachment of chlorophyll and enzymes that carry out the first stage of photosynthesis.
2) Fluid of the stroma- possesses all enzymes needed to carry out second stage of photosynthesis.
3) Chloroplasts- contain DNA and ribosomes so they can easily manufacture proteins needed for photosynthesis.
State the 2 features of cell walls…
1) they consist of a number of polysaccharides like cellulose.
2) there is a thin layer called the middle lamella which marks the boundary between adjacent cell walls and cements adjacent cells together.
State the three functions of the cellulose cell walls…
1) to provide mechanical strength in order to prevent the cell bursting under the pressure created by osmotic entry of water.
2) to give mechanical strength to the plant as a whole
3) to allow water to pass along it and so contribute to the movement of water through the plant.
State the four things a microorganism must do to be considered a pathogen…
1) gain entry to the host
2) colonise the tissues of the host
3) resist the defences of the host
4) cause damage to the host tissues
How does an infection occur?
An infection occurs if a pathogen gets into the host and colonises its tissue.
When does a disease occur?
A disease occurs when an infection leads to recognisable symptoms in the host.
What is transmission?
When a pathogen is transferred from one individual to another.
Name the two ways pathogens cause disease…
1) damaging host tissues
2) by producing toxins
State three ways the body protects itself once a pathogen has entered the body…
1) a mucus layer that covers exchanged surfaces forms a thick sticky barrier which is difficult to penetrate.
2) the production of enzymes to break down the pathogen
3) the production of stomach acid which kills microorganisms
What are the two parts of digestion?
Physical breakdown and chemical digestion.
What do carbohydrases break down?
Carbohydrases break down carbohydrates ultimately to monosaccharides.
What do lipases break down?
Lipids (fats and oils) into glycerol and fatty acids.
What do proteases break down?
Proteins ultimately to amino acids.
Explain the role of the Oesophagus in the digestive system…
It carries food from the mouth to the stomach. It made up of a thick muscular wall.
Explain the role of the Stomach in the digestive system…
It’s role is to store and digest food, especially proteins. It has glands which produce enzymes. It also has glands which produce mucus which prevents the stomach being digested by its own enzymes. It is acid to kill any microorganism and correct conditions for pepsin enzyme to work.
