Chapter 3 (Cell Structure & Function) Flashcards
What are the characteristics of living things?
Cellularity: organized membrane bound structure that
performs life fxns
Growth: ↑ in size by assimilation (taking in nutrients & using
compounds to make new cell parts)
accumulation: packing material onto cell to make
bigger ex: like build snowman
Metabolism: ability to take in nutrients & use them to provide
energy & build structures
Reproduction: ↑ in number; asexual: prokaryotes single cell
(budding)
Sexual: 2 parental cells
Responsiveness: make changes due to environment
Short term: taxis, enzyme concentrations, transport
Long term: adaptation and evolution of species
What is natural selection?
How does natural selection lead to change in a species? (Hint: think about the antibiotic-resistance example)
some individuals will produce more offspring. Traits of those that reproduce more will predominate in future generation
Natural selection leads to adaptation & evolution of species
When apply antibiotics to a population you get chance to see which cells are resistant to antibiotics
Describe the cell theory
-the cell is the basic unit of like
-all living things are composed of one or more cells
-all cells come from other cells
Prokaryote Cells
o Size
o Nucleus? Organelles?
o Cell wall chemistry
o Ribosomes
o External structures
o DNA
Size: smaller
No Nucleus & organelles
Cell Wall: provide structure & shape protect from osmotic forces
Bacterial cell wall: composed of peptidoglycan- long strings
of alternating N- acetylglucosamine
(NAG) & N-acetylmuramic(NAM)
Ribosome: 70S
External Structures:
Eukaryote cells
o Size
o Nucleus? Organelles?
o Cell wall chemistry
o Ribosomes
o External structures
o DNA
Size: bigger than prokaryotes
Nucleus & organelles: yes
Ribosomes: 80S
External structures:
Eukaryote flagellum
o Structure (basal body-hook-filament vs. 9+2 or 9+0 arrangements)
o Function – how does the flagellum move? How does the organism move?
Basal body & filament, no hook b/c don’t rotate
Basal body: 9+0 (none in center) arrangement in 3s
Filament: 9+2 (2 in middle) arrangement in pairs
Function: Moves in undulation (waving) no run and tumble
Prokaryote flagellum
o Structure (basal body-hook-filament vs. 9+2 or 9+0 arrangements)
o Function – how does the flagellum move? How does the organism move?
Basal body: extend into the cell through cell membrane
through cell wall. Operates like motor
Hook: ridged hook creates bend in flagellum & filament- spins
around & around drives cell a lot better
Filament: majority of the structure
Function: “run & tumble”
Run- move straight line flagellum (CCW)- tufts of
flagella bundle & rotate together
Tumble- abrupt movement of flagellum (CW)- tufts
of flagella become unbundled
What do these words mean?
Monotrichous, lophotrichous, amphitrichous (these are all polar)
Monotrichous: one flagellum (@ one end of cell)
Lophotrichous: tuft/multiple flagella together (@one end of
cell)
Amphitrichous: one or more flagellum @ both end of the cell
What do these words mean?
o Peritrichous
cover the cell
What do these words mean?
o Taxis, chemotaxis, phototaxis, geotaxis, magnetotaxis
Define: Positive taxis & Negative taxis
Taxis: movement in response to stimulus (dif. external
environment stimulus)
-Postive taxis: movement toward stimulus ↑ # of Runs
(CCW)
-Negative taxis: movement away stimulus ↑ # of tumbles
(CW)
Chemotaxis: chemicals
Phototaxis: light
Geotaxis: gravity
Magnetotaxis: magnetic field
Phospholipid bilayer cell membranes:
o Describe the structure of a biological membrane.
o What can cross?
o What cannot cross?
-proteins up to 50%
-Fluid mosaic model: uneven distribution of proteins ( adding
& removing Proteins & phospholipids)
Functions:
1) barrier: separates inside of the cell from the outside
-semi-permeable –> not everything can cross the
bilayer
2) Respiration: location for the conversion of chemical energy
to cellular energy in some prokaryotes
-in order for respiration in membrane need to
have ETC: protons move electrons between one another
- e- get passed on to proteins in the membrane & some
proteins move a proton( hydrogen ion) across
membrane lots of changes on one side of membrane
What CAN cross: (all small & ionic, not too strongly charged)
-water
- small lipid soluble compounds (steroids)
- oxygen & CO2
What CANNOT cross:
-most hydrophilic substances
-charged compounds & ions
-ions
Phospholipid bilayer cell membranes:
Diffusion, facilitated diffusion, osmosis, active transport
Passive Transports: doesn’t require energy, just use
concentration (DFO)
Diffusion: no energy occurs across membrane from high–>low
concentration
Facilitated Diffusion: requires protein
Carrier (permease): specific to chemical
Pore(channel): general, multiple chemicals can cross the
membrane
Osmosis: diffusion of water across membrane w/ or w/o a
pore
Active Transport: use cell energy=ATP to move material from
low to high concentration(ATP broken down
to ADP + phosphate
-Uniport: just 1 molecule move across membrane
-Antiport: 1 molecule in 1 direction other
molecule in other direction against ea. other
-Symport: moves both molecules in same direction
-Coupled transport: 2 transport working together to achieve
active transport (ex: uniport & symport)
What is group translocation? Who does it?
Only occurs in bacteria- chemical is altered as it crosses the membrane (EX: E. coli & glucose)
Describe the Bacterial structures (describe structure and function)
o Glycocalyx
EXTERNAL STRUCTURE
sugar cup
function: to protect cell/allow for attachment
composed of: polysaccharides, proteins or both
2 types of glycocalyces:
1) Capsule- firmly attached to cell surface in some
pathogens protects from immune cells
2) Slime layer- loosely attached- hold more H2O used
to attach to surface & protect against
dehydration
Describe the Bacterial structures (describe structure and function)
o Flagellum
EXTERNAL STRUCTURE
Motility: ability to move through the environment
Basal body: extend into the cell through cell membrane
through cell wall. Operates like motor
Hook: ridged hook creates bend in flagellum & filament- spins
around & around drives cell a lot better
Filament: majority of the structure
Function: “run & tumble”
Run- move straight line flagellum (CCW)- tufts of
flagella bundle & rotate together
Tumble- abrupt movement of flagellum (CW)- tufts
of flagella become unbundled
Describe the Bacterial structures (describe structure and function)
o Fimbria
EXTERNAL STRUCTURE
-nonmotile structures used for attachment
-short, numerous bristle-like surface projections, made of
protein
-stick cells to one another or to a surface( biofilms) or to a host
cell(pathogen)
Describe the Bacterial structures (describe structure and function)
o Pilus
EXTERNAL STRUCTURE
- longer than fimbriae( shorter than flagella)
-hollow tube: allow DNA to be transferred donor to receptor
- “sex pilus” (conjugation pilus): DNA transfer from one cell to
another
Describe the Bacterial structures (describe structure and function)
o Cell wall
EXTERNAL STRUCTURE
Gram +: Thick- many layers of peptidoglycan
-Teichoic acids: help ions pass through wall
-Lipoteichoic acids: link cell wall to cell membrane
-Some can be acid-fast bacteria (mycobacterium)
-additional layer of mycolic acid: hydrophobic waxy
material, prevents staining with crystal violet
Gram - : Thin cell wall of peptidoglycan
-extra membrane –> outer membrane
-From inside—> out: cell membrane->thin cell wall->outer
membrane (periplasmic space-periplasm-)
-Outer membrane: phospholipids, channel proteins,
LPS: lipopolysaccharide (lipid A+ polysaccharide)
-lipid A: also an endotoxin- when gram - bacteria are killed
endotoxin is releases into body which cause fever,
vasodilation, shock, blood clotting
-antibiotics: w/gram- infection want to stop
infection but antibiotic complicated
Describe the Bacterial structures (describe structure and function)
o Cytoplasm
INTERNAL STRUCTURE
- the liquid & structures inside the plasma membrane
Cytosol: the liquid portion of cytoplasm contains:
water, ions, carbs, proteins, lipids, waste
Describe the Bacterial structures (describe structure and function)
o Nucleoid
INTERNAL STRUCTURE (cytoplasm)
Contains DNA + proteins usually forms on single circular chromosome
Describe the Bacterial structures (describe structure and function)
o Inclusions
INTERNAL STRUCTURE
Storage deposits; varies with species
-contains : starches, lipids, sulfur (energy storage for
metabolism of cell), magnetic (allow organism to
figure out magnetic field & figure where to move),
gases, bouncy allow to float
-Polyhyroxybutyrate: PHB= lipid material used to make
biodegraded plastic
Describe the Bacterial structures (describe structure and function)
o Ribosomes
INTERNAL STRUCTURE (cytoplasm)
Site of protein synthesis
-Location throughout cytoplasm
-Size:70S s=sedimentation (how dense)
-Structure: 2 subunits (large & small: made of protein +
ribosomal RNA rRNA -rRNA backbone to subunit-)
Describe the Bacterial structures (describe structure and function)
o Cytoskeleton
INTERNAL STRUCTURE
-simple network of fibers beneath cell membrane- provide shape to cell
-not all bacteria have this structure
Describe the Bacterial structures (describe structure and function)
o Endospores
INTERNAL STRUCTURE
-made during period of starvation
-extremely resistant to: desiccation ,heat ,radiation, chemicals
-can survive for decades
-once food is available, they “wake up” or germination
-Bacillus & Clostridium
-Start as vegetative cells then starve and endospores then when nutrient available germinate and back to vegetative cells
Describe the Bacterial structures (describe structure and function)
o DNA
nucleoid
Describe the Bacterial structures (describe structure and function)
o thylakoids
INTERNAL STRUCTURE
membrane sac w/ ETC required to make chemical energy from light
-only bacteria that use sunlight as energy source ex: spirulina
-infolding the cell membrane = more SA of ETC
Compare/contrast a Gram-negative bacterium and a Gram-positive bacterium
Be able to draw what these look like (membrane, cell wall, periplasm, teichoic acids, LPS, etc.)
Describe the process of binary fission. Who does this? Why?
all reproduce asexually–> no true sexual reproduction
asexual reproduction occurs in most prokaryotes by binary fission(split in two)–> cytokinesis
Describe the process of endospore formation. Who does this? Why?
o Why do we care if endospores exist?
1) DNA is replicated –>vegetative cell
2) Cytoplasmic membrane invaginates to form forespore
3) Cytoplasmic membrane grows & engulfs forespore within a
second membrane vegetative cell denigrates
4) a cortex of peptidoglycan is deposited between the
membranes ,meanwhile dipicolinic acid & calcium ions
accumulate within the endospore
5) spore coat forms around endospore
6) endospore matures. Completion of spore coat ↑ in
resistance to heat & chemicals by unknown processes
7) endospore is released from original cell
Allows the bacterium to produce a dormant and highly resistant cell to preserve the cell’s genetic material in times of extreme stress. Survive for decades
Know the meaning of these words:
coccus, bacillus, spirillum, spirochete, vibrio, pleomorphic
tetrads, sarcinae, palisade, “V shaped”
Coccus: spherical
Bacillus: rod-like
Spirillum: spiral stiff
Spirochete: spiral flexible
Vibrio: curved (moon like)
Pleomorphic: varies in shape & size
Tetrads: four (cocci)
Sarcinae: eight-cube (cocci)
Palisade: side by side (bacilli)
V shaped: (bacilli)
Know what these prefixes mean:
diplo-, strepto-, staphylo-
Diplo- : pairs (2) (bacilli & cocci)
Strepto- : a chain (bacilli & cocci)
Staphylo- : a bunch (cocci)
Describe the Archaeal structures (describe structure and what they are for)
o Glycocalyx
EXTERNAL STRUCTURE
similar to bacteria; functions in biofilm formation
Capsule & slime layer
Describe the Archaeal structures (describe structure and what they are for)
o Flagellum
EXTERNAL STRUCTURE
-Hook, basal body, filament- built dif. proteins & assembles dif.
-Built dif. smaller, slower than bacteria
-Dif. power source= ATP ( H+ in bacteria)
Describe the Archaeal structures (describe structure and what they are for)
o Fimbriae & Pili
EXTERNAL STRUCTURE
Used for attachment
Describe the Archaeal structures (describe structure and what they are for)
o Hami
EXTERNAL STRUCTURE
attachment structure unique to archaeal cells
1) grappling hook
2) Prickles: helps attach to cells to surfaces
Describe the Archaeal structures (describe structure and what they are for)
o Cell wall
-Most have cell wall but NOT made of peptidoglycan
-Composed pf polysaccharides or proteins (or both)
-structure varies-
Describe the Archaeal structures (describe structure and what they are for)
o Cell membrane
-functionally similar to bacteria , sometimes one layer (not
bilayer)
-Use dif. phospholipids than other organisms
-fatty acids can be branched
- either covalent bond between fatty acid & glycerol (not
ester linkage)
Describe the Archaeal structures (describe structure and what they are for)
o Cytoplasm
INTERNAL STRUCTURE
liquids & structures inside the plasma membrane
-cytosol: dissolved minerals, gases
-histones- beads & string (like eukaryotes)
Describe the Archaeal structures (describe structure and what they are for)
o Cytoskeleton
INTERNAL STRUCTURE (cytoplasm)
yes
Describe the Archaeal structures (describe structure and what they are for)
o Nucleoid
INTERNAL STRUCTURE (cytoplasm)
DNA
-one circular chromosome (like bacteria) with structure similar to eukaryotes
-histones (proteins)/ nucleosome=beads on string/ proteins
that DNA winds around
Describe the Archaeal structures (describe structure and what they are for)
o Ribosomes
INTERNAL STRUCTURE (cytoplasm)
Same size as bacteria (70S)
Describe the Archaeal structures (describe structure and what they are for)
o DNA
nucleoid histones
Compare and contrast Archaea and Bacterial cells (what’s the same? What’s different?)
SAME: glycocalyces, flagella, fimbriae, pili
DIFFERENT: -Hami,
-cell wall not made of peptidoglycan
(polysaccharides & proteins instead)
-cell membrane sometimes 1 layer,
-use dif. phospholipids & covalent bonds between
-fatty acid & glycerol (not ester linkage)
-ribosome same size dif. bacteria
-nucleoid histones (proteins)
Describe these Eukaryotic structures (describe structure and what they are for)
o Glycocalyx
EXTERNAL STRUCTURE
-not as organized as prokaryotes
-only found in cells w/o cells walls(animals)
-anchored to cell membrane by covalent bonds to membrane
proteins & lipids
PROVIDES
-protection against dehydration(holds H2O)
-attachment
-reinforcement of cell membrane
-communication (traps chemical signals)
Describe these Eukaryotic structures (describe structure and what they are for)
o Cell wall
plants, algae, fungi cells have walls (not animals)
FUNCTIONS:
-protection from environment
-shape the cell
-support against osmotic pressure
Composed of: various polysaccharides–> not peptidoglycan
-plants=cellulose
- fungi= chitin
-algae= various –> cellulose, agar, carrageenan
Describe these Eukaryotic structures (describe structure and what they are for)
o Cell membrane
-semi-permeable phospholipid bilayer; fluid mosaic model
-contains STERIOD LIPIDS (animals=cholesterol) to help keep membrane fluids
-passage of materials: diffusion, facilitated diffusion, osmosis,
and active transport
-no group translocation
- Vesicular transport: moving materials in & out around
the cells w/ vesicles (spheres of membranes
- endocytosis (in) & exocytosis (out)
(not a lot of eukaryotes can do this )
Describe these Eukaryotic structures (describe structure and what they are for)
o Flagellum
INTERNAL STRUCTURES (organelles; nonmembranous)
-moves by undulation (waving motion), no run & tumble
-basal body & filament no hook b/c no rotation
STRUCTURE:
-tubulin forms hollow tubes–> microtubules
-basal body: 9+0 (arrangement in triplets & none in center)
-filament: 9+2 (arrangement in pairs & 2 in center)
Describe these Eukaryotic structures (describe structure and what they are for)
o Cilia
INTERNAL STRUCTURES (organelles; nonmembranous)
-cover the surface of the cell
-same structure as flagellum but short & numerous
-used in unison to move the organism forward
Describe these Eukaryotic structures (describe structure and what they are for)
o Ribosome
INTERNAL STRUCTURES (organelles; nonmembranous)
-Site of protein synthesis
-LOCATION: cytoplasm, rough endoplasmic reticulum
-SIZE: 80S
-STRUCTURE: 2 subunits (large & small)
made of proteins & rRNA
Describe these Eukaryotic structures (describe structure and what they are for)
o Cytoskeleton
INTERNAL STRUCTURES (organelles; nonmembranous)
-extensive network of internal fibers
-anchors or moves organelles, membrane changes for
vesicular transport, amoeboid movement, maintains cell
shape
-made of 3 types pf filaments
1) Microtubule (largest)
-tubulin
2) Microfilament (smallest)
-actin
3) Intermediate filament
- protein
Describe these Eukaryotic structures (describe structure and what they are for)
o Centrosome & centriole
INTERNAL STRUCTURES (organelles; nonmembranous)
CENTROSOME: functions during cell division (mitosis &
cytokinesis) of many eukaryotes (not in
fungi/plants)
-one centrosome = 2 centrioles @ right angles to ea.
other, near the nucleus
CENTRIOLE: made up of microtubules “9+0” arrangement of
triplets
Describe these Eukaryotic structures (describe structure and what they are for)
o Nucleus
INTERNAL STRUCTURE (organelles; membranous)
-nucleoplasm: liquid portion of nucleus
-contains one or more nucleoli (sing: nucleous->make
ribosome subunits)
-Chromatin: DNA + histones protein
-DNA wound around histones proteins from nucleosome
-Nuclear envelope:
-made up of 2 membranes that fuse together at locations
called nuclear pores
Describe these Eukaryotic structures (describe structure and what they are for)
o Nucleolus
INTERNAL STRUCTURE (organelles; membranous)
-In nucleus makes ribosome subunits
Describe these Eukaryotic structures (describe structure and what they are for)
o Endoplasmic reticulum (smooth and rough)
INTERNAL STRUCTURE (organelles; membranous)
ER: network of membranous tubes; continuous w/ the outer membrane of the nuclear envelope
- rough ER: protein synthesis occurs here b/c there are
attached ribosome
-smooth ER: No ribosomes, site of lipid synthesis
- lipids & proteins made in the ER are transported to other
parts of the cell by vesicular transport
Describe these Eukaryotic structures (describe structure and what they are for)
o Golgi body
INTERNAL STRUCTURE (organelles; membranous)
-series of flat membranous sacs
-“post office of the cell”
-receives vesicles of stuff (proteins & lipids)
-packages (+ chemical groups)
-sends packaged stuff to other parts of the cell or out of the
cell
-vesicular transport: moving material around the cell using
membranous vesicle
Describe these Eukaryotic structures (describe structure and what they are for)
o Lysosome
INTERNAL STRUCTURE (organelles; membranous)
VESICLE ORGANELLES
-in animal cell (“recycle bins”)
- contain enzymes that break down cell parts
-destroy an invading prokaryotes
- open into the cytoplasm for “suicide” (apoptosis)
Describe these Eukaryotic structures (describe structure and what they are for)
o Peroxisome
INTERNAL STRUCTURE (organelles; membranous)
VESICLE ORGANELLES
-specific type of lysozome (“toxin neutralizer”)
-enzymes destroy poisonous metabolic waste (hydrogen
peroxide free radicals)
Describe these Eukaryotic structures (describe structure and what they are for)
o Vacuole
INTERNAL STRUCTURE (organelles; membranous)
VESICLE ORGANELLES
-plants & algae store starch, lipids, water, etc.
-usually the largest part of a cell
Describe these Eukaryotic structures (describe structure and what they are for)
o Mitochondria
INTERNAL STRUCTURE (organelles; membranous)
Site of cellular respiration
-found in respiratory eukaryotes (animals & cells that are
photosynthetic
-two phospholipid bi layer membranes
1) inner membrane: has many fluids(cristae)- create more SA
-Cristae contain ETC to convert chemical energy to
ATP(respiration)
2) outer membrane: fairly permeable important for getting
ATP made in mitochondria-> have their own DNA &
ribosomes (70S); make few proteins the rest are coded by
the cell’s DNA
Describe these Eukaryotic structures (describe structure and what they are for)
o Chloroplasts
INTERNAL STRUCTURE (organelles; membranous)
-harvest light for photosynthesis
-Two phospholipid bilayer membranes (outer & inner)
- found in photosynthetic eukaryotes (algae, green plants)
-contains thylakoids: membranous sacs which contain the
pigments & ETC to convert light to ATP (photosynthesis)
- outer membrane -> inner membrane -> stroma: synthesis
part occurs, used to move sugars -> Granum: all inter-
connected (each individual is a thylakoid)
-light rxns are in granum & thylakoids
Describe these Eukaryotic structures (describe structure and what they are for)
o DNA
nuclei
What is vesicular transport?
moving materials in & out around the cells w/ vesicles (spheres of membranes
- endocytosis (in) & exocytosis (out)
(not a lot of eukaryotes can do this )
Compare/contrast exocytosis and endocytosis.
What is phagocytosis? Pinocytosis?
ENDOCYTOSIS:
1)phagocytosis (“eating cell”): import solid materials into the
cell
2) Pinocytosis (“drinking cell”): liquid into cell
EXOCYTOSIS: eliminating wastes from cell using a vesicle to
fuse w/ cell membrane
