OCR A Level Biology Cell Structure

Animal Cell Structure

Plant Cell

Prokaryotic Cell Structure

The [blank_start]Nucleolus[blank_end] is the ‘brain’ of a cell. This is surrounded by the [blank_start]Nucleus[blank_end], which in turn is surrounded by the [blank_start]Nuclear Envelope[blank_end]. The cisternae of the [blank_start]Rough Endoplasmic Reticulum[blank_end] transport substances from one area of a cell to another. This organelle also contains many [blank_start]ribosomes[blank_end] which synthesise proteins from [blank_start]mRNA[blank_end]. The [blank_start]Smooth Endoplasmic Reticulum[blank_end] contains enzymes which catalyse reactions involved with lipid metabolism. The [blank_start]Golgi Apparatus[blank_end] modifies and packages substances into vesicles. [blank_start]Lysosomes[blank_end] are full of hydrolytic enzymes which are used for the digestion of substances. [blank_start]Mitochondria[blank_end] produce ATP during [blank_start]aerobic respiration[blank_end]. They are thought to have been a foreign organism which was consumed by another single celled organism and underwent [blank_start]symbiosis[blank_end]. [blank_start]An undulipodium[blank_end] enables a cell to move (although the only human cell to have one is a spermatozoon) and [blank_start]cilia[blank_end] can push substances past a cell. Both these structures contain [blank_start]cytoskeletons[blank_end] which allow them to move. [blank_start]Vacuoles[blank_end] are found in most plant cells. They are surrounded by membranes called [blank_start]tonoplasts[blank_end]. [blank_start]Chloroplasts[blank_end] are also in plant cells. They are the site of [blank_start]photosynthesis[blank_end]

Select all the processes that occur during DNA transcription.