Cell structure Flashcards
describe the function and structure of the cell-surface membrane
function is to regulate movement of substances into and out of cell
- a bilayer of lipids (phospholipid)
- large surface area
describe the function and structure of the nucleus
function is to control reactions within the cell
- has a double membrane
- contains genetic material
- has pores so substances can move in and out
- nucleolus which manufactures rRNA and assembles ribosomes
- nucleoplasm - jelly-like material
describe the function and structure of the mitochondrion
function is to release energy during aerobic respiration
- has a double membrane
- has a folded inner membrane
- folds are called cristae
- inner fluid is called matrix
- high surface area for more efficient respiration
describe the function and structure of the chloroplast
function is to absorb light energy during photosynthesis
- has a double membrane
- folded inner membrane
- folds are called thylakoid
- chlorophyll within thylakoid
- liquid is called stroma
- high surface area for more efficient photosynthesis
describe the function and structure of the Golgi apparatus
function is to process and package polypeptides for exocytosis
- a stack of fluid-filled membrane-bound sacs
- have a high surface area
describe the function and structure of the lysosomes
function is to hydrolyse unwanted material using hydrolytic enzymes
- a vesicle containing enzymes
- lots in one cell for faster breakdown
describe the function and structure of the ribosomes
function is for protein synthesis during translation
- made up of 2 sub-units
- consist of proteins and rRNA
- no membrane so sub-units can move
- 80s in plant cells and 70s in prokaryotic cells
describe the function and structure of the RER
function is to transport polypeptides
- a fluid-filled membrane
- covered in ribosomes
- large surface area
describe the function and structure of the SER
function is to process and synthesise lipids
- fluid-filled membranes
- large surface area
describe the function and structure of the cell wall
function is to support and maintain shape of cell
- made from cellulose - condensation of beta glucose molecules form fibrils - fibrils joined by hydrogen bonds which collectively provide strength
- found on the surface of plant, algal and fungal cells
- arrangement of fibres gives strength
describe the function and structure of the cell vacuole
function is to maintain the shape and pressure of the cell, and to move chemicals
- membrane-bound (tonoplast)
- within the cytoplasm
- contains cell sap
- membrane separates sap from cytoplasm
describe how a lysosome can break down eg. proteins
- the lysosome will fuse with the faulty protein and the phospholipid biolayers will join together to become 1
- the hydrolytic enzymes within the lysosome are released which will break down the protein into amino acids
- exocytosis then occurs (when the waste molecules leave the cell)
name the structures found within prokaryotic cells
- cell wall made from murein
- cell membrane
- slime capsule (for protection)
- DNA loop
- ribosomes (70s)
- flagellum for mobility
- plasmid which can transfer DNA to other cells
describe how light microscopes work
- light from a mirror is reflected up through the object into the objective lens
- the image produced is magnified by the eyepiece lens
describe how an SEM microscope works
- a beam of electrons is produced at the top of the microscope by an electron gun
- the electron beam follows a vertical path through the microscope held within a vacuum