A2.2 - Cell Structure Flashcards
cell theory
all living things are made of one or more cells
magnification triangle formulas
I = A x M
A = I/M
M = I/A
characteristics of light microscopes
low magnification & resolution (20,000x)
inexpensive
easy specimen preperation
specimen can be living
characteristics of electron microscopes
greater magnification & resolution (500,000x)
expensive
lengthy specimen preperation
black and white (unless using fluorescent stain)
kills cells
fluorescent stains
absorb then re-emit light at different wavelengths (brightnening)
immunofluorescence
uses antibodies to bind to different structures
how does immunofluorescent stains work
different fluorescent stains bind to different antibodies to create different colored images
process of freeze fracture electron microscopy
rapidly freeze a sample
steel blade fractures sample at weakest point
ice is removed
platinum vapor attaches to create replica of surface
only viewed in electron microscope
helpful for understanding membrane 3D structure
Cryogenic Electron Microscopy (Cryo - EM)
freezes layer of protein
viewed on electron microscope
computer looks for pattern
can see individual atoms
allows for understanding of protein structure
how many micrometers is 1 mm
1000 micrometers
structures common to all living organisms
DNA
Cytoplasm
Cell Membrane
DNA
stores genetic information to code for proteins
Cytoplasm
water based solution where metabolic reactions occur (ex: respiration)
Plasma Membrane
semi permeable phospholipid bilayer
characteristics of prokaryotic cells
simple, small,
lack nucleus
non-compartmentalized
have cell wall
naked DNA (no histones)
70’s ribosomes
characteristics of eukaryotic cells
larger than prokaryotes
have cell wall
compartmentalized
80’s ribosomes
have nucleus & mitochondria
processes of life (MR.SHENG)
metabolism
reproduction
stimuli response
homeostasis
excretion
nutrition
growth
metabolism def
sum of all enzyme catalyzed reaction in a cell
reproduction def
production of offspring
stimuli response def
internal & external reactions
homeostasis def
maintenance of stable internal environment
excretion def
removal of excess waste
nutrition def
getting nutrients required for growth & maintenance
growth def
increasing in size & number of cells
examples of unicellular organisms
paramecium
chlamydamonas
components of paramecium
cilia
contractile vacuole
nucleus
food vacuole
cytoplasm
components of chalmydamonas
flagella
nucleus
contractile vacuole
chloroplast
eye spot
features exclusive to animal cells
centrioles
undulipodia (cilia, flagellum)
features exclusive to plant cells
plastids (choloroplast)
cell wall
vacuoles
exceptions to cell theory
RBC - no nucleus or DNA
phloem sieve tubes - nucleus & organlles break down, rely on companion cells
skeletal muscle - multi-nucleiated
aseptate fungal hypahe: walls that separate cells are absent (aseptated: not separate)
distinguishing features of prokaryotes in microscopy
(shape, size & features)
rod or round, spiral shape
smaller than 10 micrometers
no membrane bound organelles
distinguishing features plant cells in microscopy
geometric/rigid shape due to cell wall
look for chloroplast & central vacuole
distinguishing features of animal cells in microscopy
no central vacuole
no chloroplast
organelles found in eukaryotes (13)
nucleus
rough ER, smooth ER
golgi apparatus
lysosome (animals)
mitochondira
free ribosomes
chloroplast (plant)
vacuole & vesicle
microtubules
centrioles
cytoskeleton
cilia & flagella
nucleus
double membrane
holds chromosomes
DNA w/ histones
makes ribosomes
Rough endoplasmic reticulum
flat cisternae w/ ribosomes
synthesis of proteins
uses vesicles to pass proteins to golgi
smooth endoplasmic reticulum
branched membranes
synthesizes lipids (smooth = oily)
golgi apparatus
flat, curved cisternae
processes proteins from rER
lysosomes
sphere containing enzymes for digestion (lipase)
darkly stained in micrograph
mitochondria
site of aerobic respiration (Krebs)
couble membrane
inner membran contains cristae
free ribosomes
small, dark structure
no membrane
synthesizes proteins (rRNA)
chloroplast
double membrane
stacks of thylakoid discs
photosynthesis
vacuoles
store water (central vacuole)
large in plants
small in animals
used by unicellulars to get rid of excess water (homeostasis)
vesicles
very small vacuole
used for transport
proteins= rER –> Golgi
microtubules
small cylindrical fibers
move chromosomes in cell division
centrioles
found in animal cells
anchor point for microtubules
cytoskeleton
protein fibers
easily break down & reform
maintenance of shape
moves parts around cells
cilia & flagella
made of microtubules
used for movement
flagella = longer & fewer
cilia = shorter & many
