Studied by 3 people
eukaryote
complex, multicellular, membrane bound organelles, 0.1mm animal, plant, agal, fungal
cell surface / plasma membrane
membrane found on surface of animal cells and inside the cell wall of other cells; regulates movement of substances in and out of cell
cytoplasm
fluid inside cell which metabolic reactions occur in
nucleus
large, nuclear envelope double membrane, pores, nucleolus, chromatin; contains genetic material and controls cell’s activity, pores allow RNA to move into cytoplasm
nucleolus
produces ribosomes
mitochondria
double membrane, inner membrane folded into cristae, matrix, respiratory enzymes; site of aerobic respiration
Golgi apparatus
a group of fluid filled membrane bound flattened sacs; processes and packages new proteins and lipids and produces lysosomes
Golgi vesicle
a small fluid filled membrane bound sac produced by the Golgi apparatus; stores processed lipids and proteins and transports them out of the cell
lysosome
round membrane bound organelle; contain digestive enzymes called lysozymes which digest invading cells or dead/broken components
ribosome
very small, attached to RER, 80s, made of proteins and RNA not surrounded by membrane; site of protein synthesis
rough endoplasmic reticulum - RER
large fluid filled membrane bound flattened sacs with ribosomes on surface; folds and processes proteins made at ribosomes, site of protein synthesis
smooth endoplasmic reticulum
large fluid filled membrane bound flattened sacs; synthesises and processes lipids
cell wall
rigid structure that surrounds plant cells, plant and algae cellulose, fungi chitin; supports cell structure and prevents cell changing shape
chloroplast
plant cells only, double membrane, matrix, starch granules, thylakoids stacked, grana linked by lamellae; site of photosynthesis
vacuole
membrane bound sac containing sap, tonoplast membrane; storage, maintains internal cell pressure to stay rigid and prevent wilting
epithelial cells
villi and microvilli increase surface area for absorption, lots of mitochondria for cotransport
red blood cells
no nucleus, biconcave, increase amount of oxygen that can be carried
sperm cells
lots of mitochondria for energy for movement towards egg
tissue
group of cells working together to perform a particular function
organ
different tissues working together
organ system
different organs working together
prokaryote
simple single celled organism, no membrane bound organelles, less than 2 micrometers
prok membranes
cell surface membrane and cell wall, cell wall made of murein glycoprotein
slime capsule
protect bacterium from attack by immune system cells
prok ribosomes
70s smaller than euk; site of protein synthesis
flagellum
long hairlike structure, rotates; moves bacteria
prok genetic material
free in cytoplasm, circular, not associated with histones, plasmids passed between prokaryotes
virus
acellular, capsid protein coat, attachment proteins, genetic core, replicate using host cell mechanisms
binary fission
DNA and plasmids replicate
cell expands DNA moves to opposite poles
cytoplasm divides new cell wall formed
two daughter cells, random assortment of plasmids
viral replication
virus attaches to receptor proteins, complimentary
genetic material released into host cell
gm replicated by host cell machinery
viral components assemble
new viruses released from host cell
magnification
how much bigger the image is compared to the specimen
magnification = size of image / size of real object
resolution
how well the microscope distinguishes between two close points
optical microscope
uses light, max magnification x1500, max resolution 0.2 micrometers
electron microscope
uses electrons, more detailed, max magnification x1500000, max resolution 0.0002 micrometers
transmission electron microscope TEM
electromagnets focus beam of electrons transmitted through specimen, denser absorb more electrons darker image, see internal structures, vacuum, thin, dead specimen
scanning electron microscope SEM
scan a beam of electrons across specimen, knocks off electrons from specimen collected to form image, 3D image, surface only, thick specimen, lower resolution
artefact
object visible down microscope that isn’t part of the specimen
cell fractionation
homogenisation break up membranes release organelles,
filtration through gauze remove large debris,
ultracentrifugation spin in centrifuge increasing speed, largest organelles separate first
drain supernatant and remove pellet
cell fractionation properties
ice cold reduce enzyme (lysozyme) activity, isotonic prevent cell lysis, pH buffer maintain pH prevent denaturing
mitosis
cell division of somatic cells, 2 genetically identical daughter cells
interphase
G1 growing, S DNA replication, G2 growing, normal cell function throughout
prophase
chromosomes condense, nuclear membrane break down, centrioles move to opposite poles
metaphase
chromosomes line up along equator, spindle fibres attach to centromere
anaphase
spindle fibres contract separating sister chromatids, pulled to opposite poles of the cell
telophase
chromatids uncoil, nuclear envelope reform around each pole
cytokinesis
cytoplasm divides producing two separate genetically identical daughter cells
mitotic index
mitotic index = number of cells with visible chromosomes / total number of cells visible
