Topic 2 a Flashcards
Name the extra organelles in plant cells
Cell wall, chloroplasts, cell vacuole
Describe the differences between a fungal and plant cell
Fungal carbohydrate = murein
Plant carbohydrate = chitin
Describe the cell surface membrane
memebrane found on the surface of animal cells and inside the cell wall of plants. Mainly made of lipids and proteins
Give two functions of the cell surface membrane
Regulates movement of substances in and out of the cell. Has receptor molecules allowing it to respond to chemicals eg hormones
Describe the structure of the nucleus
Large organelle surrounded by a nuclear envelope containing many pores. Contains many chromosomes associated with histones and a nucleolus, both within the nucleoplasm
What is function of the nucleus?
Acts as a control centre through the production of mRNA and tRNA and hence protein synthesis.
Retains the genetic material of the cell in DNA anc chromosomes.
Manufactures ribosomal RNA and ribosomes
Describe the mitochondria
Oval shaped and have a double membrane, the inner is folded to create the cristae and inside the cristae is the matrix.
What is the mitochondria responsible for, where are they usually found
They are the site of aerobic respiration where ATP is produced.
Found in large numbers in cells that are very active and require a lot of energy.
Cristae provide a large surface area for the attachment of enzymes and other proteins involved in respiration
Describe the structure of the chloroplast
Small flattened structure found in plant and algal cells. Has a double membrane and also contains thylakoid membranes which are stacked to form the grana which are linked by lamallae. There is also a thick fluid- stroma
What is the function of a chloroplast
The site of photosynthesis.
The thylakoid membranes contain the photosynthetic pigment chrorphyll- this is where the first stage- light absorption takes place. Also has a large surface area for the attachment of chlorophyll, electron carriers and enzymes.
The stroma is where the 2nd stage- synthesis of sugars takes place- also contains starch grains and enzymes needed to make sugars.
Describe the appearance of the golgi apparatus
Consists of stack like membranes that make up cisternae containing vesicles.
What is the golgi responsible for
The proteins and lipids produced by the ER are passed through the golgi apparatus and then modified by adding carbohydrates to form glycoproteins. Then sorts the modified proteins and lipids and transports them in Golgi vesicles which are pinched of from the ends of the golgi cisternae, these vesicles move to the cell surface where they fuse with the membrane and release their contents outside the cell.
What is a golgi vesicle and what is it responsible for
The modified proteins and lipids are transported in Golgi vesicles which are pinched of from the ends of the golgi cisternae, these vesicles move to the cell surface where they fuse with the membrane and release their contents outside the cell.
