Cell structure Flashcards
1mm is how many micrometres
1000
1 micrometre is how many nanometres
1000
Magnification
The number of times larger an image is, compared to the real size of the object
Resolution
Ability to distinguish between two points
Greater resolution=greater detail
Cell surface membrane
Extremely thin
Composed of phospholipids
Partially permeable
Allows the movement of substances into and out of the cell
Nucleus
Largest organelle
Contains dna in the form of chromatin
Surrounded by double membrane
Nuclear envelope has many small nuclear pores that allow the exchange of substances between the nucleus and the cytoplasm
Nucleolus
Inside nucleus
Synthesises rRNA and makes ribosomes
Rough endoplasmic reticulum
Covered with ribosomes
Protein synthesis
Smooth endoplasmic reticulum
No ribosomes
Synthesises lipids abs steroids
Golgi apparatus
Stack of flattened sacks
Constantly being broken down and formed from vesicles
Protein modification
Synthesises glycoproteins
Mitochondria
Cytoplasm Surrounded by two membranes Inner membrane folds to form cristae Produces ATP through aerobic respiration 70S ribosomes
Ribosomes
Attached to rough er or free in the cytoplasm Consists of two subunits 80S in cytoplasm 70 in chloroplasts and mitochondria Site of protein synthesis
Lysosomes
Found in cytoplasm
Digest unwanted material (old organelles and cells)
Contain hydrolytic enzymes
Microtubules
Rigid, hollow tubes in cytoplasm Support Involved in movement of organelles Form spindle used to separate chromatids Make up centrioles
Chloroplasts
Plant cells
Site of photosynthesis
Contain chlorophyll