Cell Structure Flashcards
Who discovered cells in what year?
What word does the word ‘cell’ come from?
Robert Hooke in 1665
Cellula
Define: prokaryotic cell
A small, unicellular unit which stores a singular, circular chromosome of DNA but lacks a membrane bound nucleus and usually other organelles
Define: eukaryotic cell
A larger unit which has organelles and a membrane bound nucleus
Define: unicellular
An organism made up of only one cell
Define: organelles
Membrane bound regions of specialised function within a cell which is held in place by the cytoskeleton and are usually enclosed by a lipid bilayer
Define: nucleus
What type of cells is it found in?
Describe its structure
The control centre of a cell which contains its DNA
Found in all cells except for prokaryotes
Large and oval in shape, surrounded by a nuclear envelope (a double membrane with pores) and may contain one or more nucleoli (site of ribosome synthesis)
Define: mitochondrion
What type of cell is it found in?
Describe its structure
The site of aerobic cellular respiration in which ATP is produced
Found in all cells except prokaryotes
Peanut shaped; has a double membrane - the outer membrane is smooth and the inner membrane is folded into cristae
Define: chloroplast
What type of cells is it found in?
Describe its structure
The site of photosynthesis in plant cells
Only found in plant cells
Green (due to chlorophyll) and oval shaped; double membrane - the inner membrane has stacks (grana) made from smaller sacks (thykaloids) and has a gel like innermost substance called stroma
Define: ribosome
What type of cell is it found in?
Describe its function
The cell’s site of protein synthesis, made of rRNA and protein
Found in all cells
Not enclosed by a membrane; either freely floating in the cytosol (proteins for the cell) or attached to the ER (proteins for secretion)
Define: endoplasmic reticulum
What type of cell is it found in?
Describe its function
A branched network of channels made of membrane that transport molecules within the cell
Found in all cells except prokaryotes
Connects to the nuclear envelope and cell membrane; the rough ER creates proteins and is embedded with ribosomes, the smooth ER creates lipids and steroids
Define: Golgi apparatus
What type of cell is it found in?
Describe its function
Packages and exports proteins outside the cell and modifies proteins made by the cell
Found in all cells except prokaryotes
Made of layers of membrane - stacks of flattened sacks
Define: lysosome
What type of cell is it found in?
Describe its function
A membrane sac containing enzymes for apoptosis (programmed cell death)
Common in animal cells, uncommon in plant cells
Small and round with a single membrane; has digestive enzymes which break down food molecules and digests old cell parts
Define: cell
The basic structural and functional unit of all known living organisms
