Unit 2: cells Flashcards
Cell Theory
- all cells are composed of one or more cells
- the cell is the basic unit of structure + orginization in organisms
- all cells come from preexisitng cells
Compound light microscope
a high magnification microscope that uses 2 lenses to compound (multiply) the level of magnification
Plasma membrane
a microscopic membrane of lipids and proteins which forms the external boundary of the cytoplasm of a cell or encloses a vacuole, and regulates the passage of molecules in and out of the cytoplasm.
Prokaryote
no nucleus, single celled organisms, lack other organnelles
Eukaryote
an organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus. Eukaryotes include all living organisms other than the eubacteria and archaebacteria.
Cytoplasm made of
gell like substance made of water, salts, and organic molecules
Cytoplasm function
holds all the components of the cell
What cells have cytoplasm
all cells
Ribosomes made of
RNA + protein
Ribosomes function
responable for protein assembly + production
Ribosomes Prokaryotes size
70s 16S rRNA
Ribosomes Eukaryotes size
80s 18S rRNA
Nucleoid
The nucleoid is an irregularly shaped region within the prokaryotic cell that contains all or most of the genetic material.
Cell wall
protects cell + gives shapes
what cells have cell walls
plant cells + bacteria
what are cell walls made of in plant cells
cellulose
what are cell walls in bacteria made of
peptidoglycan (sugar + amino acids)
Cilia
small, slender, hair-like structures present on the surface of all mammalian cells
Fimbriae
Flagella
aid in cellular locomotion
- bacillus
-some animal cells
-few plant cells
Nucleus
the control center that contains DNA
Endoplasmic Reticulum (ER)
rough
has ribosomes, protein synthesis + folding
ER smooth
no ribosomes, lipid synthesis + detoxification
Peroxisome
enzyme - detoxifies harmful substances - break down fatty acids
lysosomes
enzyme - breaks down waste + cellular debris
Golgi apparatus
cell shipping + recieving - proteins + more
Mitochondria
power house of the cell
generates ATP
has its own DNA - size 70s 16S sRNA ribosomes
could’ve originated as a prokaryote
Cytoskeleton
a structure that helps cells maintain their shape and internal organization
Vacuole
“empty space” - hole
helps store nutrients + dispose of waste
-helps maintain pressure
Chloroplast
an organelle within the cells of plants and certain algae that is the site of photosynthesis
could have used to be prokaryote
own dna + small ribosomes
has chlorophyll
membrane
Endomembrane system
group of interconnected membranes and organelles within eukaryotic cells that work together to modify, package, and transport lipids and proteins.
Endosymbiont theory
endosymbiosis = bacteria engolfs the other one
theory = mitochondia + chloroplasts used to exist independently
-own dna
-double membranes
-same size as bacteria
-70s ribosomes
-only be produced by division of pre-existing ones
Fluid mosaic model
model of phospholipid bilayers, with cholestorol, and transport proteins and receptor proteins
Selectively permeable
some materials can pass through the cell membrane while some can’t -
small + nonpolar can pass through
Receptor protein
proteins or protein complexes located in the membrane of cells that receive chemical signals and trigger a defined cellular response
example: horomones
channel protein
a type of facilitated diffusion where molecules that are larger and/or nonpolar moved across the membrane through a protein, without using energy
Glycoprotein
Transport protein
Transport proteins act as doors to the cell, helping certain molecules pass back and forth across the plasma membrane,
Diffusion
particles moving from high concentration to low
protein pump
uses energy in the form ATP to transport materials against the concentration gradient - low –> high
example: sodium-potassium pump
Concentration gradient
the process of particles, which are sometimes called solutes, moving through a solution
high concentration -> low concentration
Passive transport
transport with no energy input
active transport
requires energy - ATP
Osmosis
facilitated transport of water across membranes with the channel protein aquaporin
Facilitated diffusion
partciles move through a channel protein
exp: glucode transport into the cell
simple diffusion
particles move directly across membrane
Aquaporin
channel protein for water
Exocytosis
moving large materials out of the cell by feusing the vesicle to the membrane
- cell becomes bigger
Endocytosis
moving large materials into the cell by folding in the membrane
-cell becomes smaller
Tonicity
number in bars that helps determine which was water will flow - the water potential - quantified
-negative = unlikely to move
positive = likely to move
Isotonic
things have same tonicity, particles move in and out at dynamic equlibrium, no cell mass change
Hypertonic
more solute outside, water moves from inside of the cell to outside, cell becomes shrivelled
hypotonic
less solute outside, water moves from outside the cell to inside, cell becomes lysed and can burst
Flaccid
cells in isotonic solutions
turgid
plump cells in hypotonic solutions
Plasmolysis
cells that are in hypertonic solutions and lost water
