205 terms

Cell

STUDY
PLAY
Cell Theory
All Living things made of cells; cells are smallest unit of life; cells come from other cells
All cells have:
Plasma Membrane
Symplast
Living part of cell
Apoplast
Outside of cell (environment)
Prokaryotic Cells (DNA)
dsDNA, long strand, circular, few proteins, "naked DNA"
Nucleoid
Region of the prokaryotic DNA
Prokaryotic Ribosomes
70S
CW protein Euk. vs Prok
Prok: peptidoglycan
Euk: Glycogen
Prokaryotic Cells DON'T HAVE
Membrane bound organelles, Complex Internal membranes (ER, Golgi), true cytoskeletons
Eukaryotic cells have
PM; Cytosol; Dual membrane organelles; haploid or diploid; complex internal membranes; cytoskeleton
Euk DNA
dsDNA; in chromatin structure most of the time; 50% DNA 50% Protein
Prokaryotic Simple -
ONLY HAPLOID
Euk Ribosomes
Large (80S)
Dual Membrane Organelles
Nucleus, chloroplast, mitochondria
Single Membrane Organelles
Lysosomes, peroxisomes, endosomes, vesicles
Unicellular Euk
Yeast paramecium, amoeba; reproduce by fission because of chromosomes and mitosis some genetic modification
Multicellular Euk
Complex organisms; reproduce sexually/asexually, sex: HIGH level of genetic modification
Storage carbs
Plants: Starch Animals: Glycogen
Peripheral vs Integral proteins
Peripheral can be washed off, attached to Phospho heads or other proteins. Integral can't be removed w/o destroying membrane embedded.
Glycoproteins
Sugars covalently attached to protein (on external side of PM)
Functions of Proteins
Enzyme, receptors, transport, cell recognition
Chromatin
DNA+Protein
Nucleolus
site of ribosome synthesis; rRNA made first, then assembled into ribosome
Nuclear Pore Complex
Regulates entry/exit of nucleus
Nuclear Lamina
Gives shape to nucleus
What is the outer membrane of the Nucleus continuos with?
The RER
Mito Outer Membrane is___, ___ allow anything up to a certain size
Permeable; porins
Mito Inner membrane acts as ___ has ___ to increase surface area also contains enzymes for ____
PM; cristae; ETC
Mito Matrix is filled with __ home of ____, also has _____ (___ version)
liquid; krebs cycle; DNA/Ribosomes, tRNA, rRNA; prokaryotic.
Chloro Reactions
Light in Grana (Contains Chlorophyll) Dark in Stroma
Chloro Stroma has __
Enzymes for photosynthesis, DNA ribosomes, Prok. Versions
Chloro membranes are similar to ___
Mito membrane
Endosymbiant Theory
Mito/Cplast may have evolved from small bacteria that were engulfed by larger bacteria during evolution of life
Evidence for Endosymbiant Theory
Both have Prok. features; 70S ribosomes, bacterial gene structure, few proteins on DNA,
Mito are distant relatives
of purple nonsulphur bacteria
Chloro are distant relatives
of cyanobacteria
Vacoule is bound by a
tonoplast
List of microbodies
Perioxisome,gloxysome, lysosome, ribosome,
Function perioxisome
breaks down peroxide
Gloxysome
breaks down fatty acids
lysosome
breaks down proteins, lipids, and nucleic acids
Ribosome
only organelle that DOESN'T have a membrane, composed of 2 subunits composed equally of rRNA and protein
Ribosomes have __ nucleotides
modified
Endomembrane system flow
Nucleus, RER, vesicles, Golgi, PM or lysosomes
Nucleus (Flow)
mRNA exits through nuclear pore to RER
RER (Flow)
Protein synthesized on ribosomes on sufrace. Enters lumen of ER where its modified
Golgi (Flow)
protein from ER is modified then transferred to PM/Organelles.
Glycosylation
Adding sugars to protein
SER
Site of lipid synthesis, drug detox, Calcium storage, connected with RER
Vesicle movement is
very specific, done via motor proteins and microtubule highway
Golgi's 2 sides
Forming/Cis side, faces ER.
Maturing/Trans side faces PM
3 Main components of cytoskeleton
Microtubules, microfilaments, intermediate filaments
Microtubules
Composed of tubulin (hollow) intracellular transport, spindle fibers
Microfilaments
composed of Actin, Located below PM, gives shape involved with different kinds of movement
Intermediate filaments
Can join between cells, nuclear lamina, scaffold of the cell, many different kinds of proteins are IF
Cell Wall - function
Protection from viruses, prevents lysing, gives shape to cell.
Cell Wall - structure
Fiber: Cellulose,
Hydrated Matrix: Hemicelloulose (carb), Extensin (Protein)
Adhesive: Pectins (carb)
CW formation
Primary CW formed first, Secondary CW formed second (2-3 layers)
CW is very ___ and ___ is tightly controlled
organized, structure
Middle Lamella
Composed of Calcium pectate, sticks cells together
Plasmodesmata
Entire outer pore complex of plant cell
Plasmodesmata function
Cell communication via SMALL chemical signals or electrical signals
Destotubulue
Connection between the ER's of both plant cells
Amount of Plasmodesmata depends on...
amount of cell communication
Extracellular Matrix is in what organism
Animals only
ECM Structure
Fiber: Collagen, elastin
Hydrated Matrix: Proteoglycan
Adhesive Molecule: Fibronectin, laminates
Gap Junctions (Connexons)
Connects Adjacent animal cells
Gap Junction Function
Communication via electrical signals (membrane potential) or small chemical signals
Main components of organic life
CHOPNS
4 Macromolecules
Carbs, Lipids, Nucleic Acids, Protein
5 bonds in organic molecules
Covalent, Disulphide, Ionic, Hydrogen, Hydrophobic interactions
Aldo vs Keto sugar
Aldo has carbonyl at the end of the chain 6 sided ring; Keto carbonyl in the middle 5 sided ring
If OH is below ring
Alpha form sugar
if OH is above ring
Beta form sugar
Bond between sugars
Glycosidic
Branches of sugars more common in ____ than ___
Glycogen; Starch
Types of polysach.
Storage Structure
Structure Polysach
Can't be broken down (beta bond) Cellulose
Storage Polysach.
Can be broken down (alpha bond)
Lipid Function
Structural, Store energy, signal molecules
Fatty Acids
Long chain HC w/ carboxyl group usually 12-20C
Phospholipid structure
Glycerol 2FA tails 1 P group - charged
FA-Phospholipids spontaneously form structures in order of complexity:
Micelles, film, bilayer
Steroids
Lipids, 4 ring structure
Steroid function
Structural (cholest) Signal (estrogen)
Terpene subunit
isoprene, 5C
NA Functions
Informational, Structural, enzymes
NA informational
DNA/RNA
NA Structural
Part of Ribosomes, 7S RNA part of SRP, snRNPs
NA enzymes
Ribozymes
Ribozymes
short RNAs that act as enzymes
NA structure
5C sugar, Nitrogenous base, Phosphate
If C2 sugar has OH
Ribose (RNA)
If C2 sugar has H
Deoxyribose (DNA)
Thymine vs. Uracil
Thymine has methyl while uracil has hydrogen
First NA has
5' Phosphate
Last NA has
3' Hydroxyl
Bonds between Nitrogenous bases
H-Bonds (3 for G-C, 2 A-T)
Bonds between backbones
Phosphodiester
Types of RNA
mRNA, rRNA, tRNA, snRNA, Ribozymes, Nucleotides, Nucleotide Derivs.
snRNA
small nuclear RNA, snRNPs
Nucleotide Derivs.
NADH, FADH2, NADPH, cAMP; high energy compounds involved in e- transport, redox reactions
DNA replication enzymes
Helicase, topoisomerase, SSBP, Primase, DNA poly 3, DNA poly 1, Ligase
PCR Purpose
Make millions of copies of a specific DNA sequence
Needed for PCR
Template DNA,
dnTPS (Deoxyribose Nucleotides, dA/G/C/TTPS)
2 Primers one for each strand
Buffer (needs Mg)
Enzyme - taq DNA poly
3 Steps of PCR
Denaturing, Annealing, Extension
Formula for amount of DNA made from PCR
2^n n=number of cycles
Two ways to do DNA fingerprinting
RFLP; PCR
Variable Number Tandem Repeat (VNTR)
How many times a DNA sequence appears
Protein Functions
Enzymes, structures, receptors, transport proteins, hormones, electron transport
Polar AA have
Carboxyl, Hydroxyl, Amino, Sulfhydrul
Charged: Carboxyl=Acidic, Amino=Basic
Bonds in Proteins
Disulfide, Hydrogen, Ionic, Hydrophobic Interactions
Disulfide bonds in proteins
Bend structure
Hydrogen in proteins
very common and important in proteins usually H + Amino or carboxyl
Primary Structure and Bonds involved
String of AA; peptide
Secondary Structure and Bonds involved
Alpha helix beta pleated sheet; H bonds
Tertiary Structure and Bonds involved
3D structure; Disulfide, ionic, hydrophobic interactions, H bonds
Quaternary Structure and Bonds involved
1+ subunit Disulfide, ionic, hydrophobic interactions, H bonds
Domain of Protein
Part of protein that does a specific function
Homeotic Gene
Genes that determine which parts of body from what body parts
Structural Motifs
Found in many proteins, do the same function
7TM
7 Transmembrane domains
Usually a G protein linked receptor
Found in both animals and plants same function
Types of structural motifs
Helix-Turn-Helix, Helix-Loop-Helix, Zinc Finger, Leucine Zipper All bind to DNA, transcription factors
Heat's effect on denaturation
Disrupts H and ionic bonds
pH's effect on denaturation
Disrupts charge of groups, ionic H bonds
Reducing Agent; Denaturation
Sulfhydrul bonds
Organic Solvent; Denaturation
Destroys entire structure
Which bond is NOT affected by denaturation?
Peptide
Few proteins ___ spontaneously
renature
Catalysts
Increase rate of reaction
Not used up by reaction
only small amount needed
Don't alter equilibrium
Steady State vs. Equilibrium
Steady state is in living cells, equilibrium in solutions
Characteristics of Enzymes
Specific, Efficient, Regulated
Substrates go through ________
activated transition states
Induced Fit Model
Enzyme confirms to substrate
Covalent Intermediates
Temporary covalent bonds between enzyme/substrate
Temp. Donation of H+ or e-
Enzyme can temp. stress substrate
Factors that affect enzyme activity
pH, Temp
small pH effect on enzyme
changes binding of protons on substrate, changes charge on sub/enzymes
may not be able to bind at all or as well
Large pH effect on enzyme
disrupt tertiary structure of protein
if partially unfolded, enzyme less active
if completely unfolded enzyme totally inactive
Additional factors needed for enzymes
Coenzymes, prosthetic group, Metal Ions
Coenzymes
Small organic molecules
Bind reversibly and noncovalentely to enzyme
Can be released
Prosthetic group
organic compound (heme)
Tightly bound to enzyme (covalent)
NEEDED FOR ENZYME TO FUNCTION
Metal Ions
Bind to enzyme or Pros. Group
Required for proper 3D structure
Allosteric Enzymes have ____ subunit
More than one
Catalytic vs. Regulatory
Cata: site of reaction, Reg: controls activity of catalytic site
Effector
small organic molecule that controls activity of enzyme
Feedback inhibition
products inhibit enzyme
Covalent Modification
Add or remove chemical groups from enzyme
Kinase
adds P group to enzyme
Phosphatase
removes P group from enzyme
Cascade Reaction
Repetition of kinase/phosphatase reactions
Proteolytic Clevage
Removal of AA to make active form of enzyme
Enzymes synthesized in an inactive form
Proenzyme, proprotein, zymogen
Reasons for Extra AA (Proteolytic)
Needed to fold protein, needed to keep protein inactive to protect cell
High levels of glucose, which pathway is turned on?
Glycogen Synthesis
Low levels of glucose which pathway is turned on?
Glycogen breakdown
cAMP
signal molecule
cAMP is normally at ___ levels. Why?
low, increase of cAMP leads to big effect, very unstable molecule
Phosphodiesterase breaks down ___
cAMP
Phosphodiesterase is always ____
active
Glycogen Synthase is usually ___
active
Glycogen Synthase is inhibited by ___
Protein Kinase A
Protein Kinase A
Regulates both pathways, Synthesis and breakdown. Target Enzymes: Glycogen Synthase, Phosphorylase Kinase
Type of regulation in glycogen synthesis
Allosteric
cAMP is made from
ATP, Adenylyl cyclase (integral membrane protein) creates it when signaled
Adenylyl Cyclase is usually ____
inactive
Phosphorylase Kinase
Adds P to phosphorylase
Phosphorylase
breaks off one glucose monomer from glycogen
Remaining phosphorylated enzymes are deactivated by (2 things)
Spontaneous hydrolysis, or specific phosphatases
Kinds of phospholipids
Phosphoglycerides, sphingolipids, glycolipids
Phosphoglycerides
Glycerol backbone+2FA+P group+Polar/Charged head group
sphingolipids
Sphingosine + 2 FA + P group +Polar/Charged head group
Sphingosine
Serine+2FA
Glycoproteins
sugar covalently attached to phospholipids (Many in sphingolipid category)
Lipid Rafts
Region in bilayer that is thicker/less fluid than rest of membrane
Outer layer of lipid raft
high layers of cholest/glycosphingolipids
Long sat. FA tails
Function of lipid raft:
Cell communication
enriched with receptor/GPI proteins
GPI protein
Glycosyl Phosphatidyl Inositol
OH from cholest can ____ to carbonyl of FA
H bond
Lipid Anchor
Attached to lipids in Bilayer
FA or isoprenyl attached groups to protein
Lipid anchor is made in ____ on ___
cytoplasm; free ribosomes
Isoprenyl Carbons
C5 Building Blocks
Farhesyl
C15
Geranyl Geranyl
C20
FA for Lipid Anchor
C14/C16
GPI is made in ___ by ____
RER; attached ribosomes
GPI is on the _____ side
enviro
Lipid anchor is on the ____
Cytoplasm
____ diffusion of lipids proteins is allowed, so is rotation
Lateral
____ movement is not allowed or spotaneous
Transverse (flip/flop)
Transition temp
temp where membrane can go from gel to fluid
Adding Unsat. FA
Increases fluidity
Hydrocarbon chain length
Larger chain - higher transition temp (less fluid)
Cholest. Membrane
High Temps: Makes Bilayer less fluid
Low Temps: Makes bilayer more fluid
Adds mechanical strength to membrane
Net ____ charge on cytoplasmic side
Negative
Net ____ charge on enviro side
Positive
Membrane Potential
Charge difference across membrane
Molecules that can pass the membrane with no proteins
Small uncharged molecules, Gases, Water, some steroids (non polar)
Can't pass through without membranes
Large, Polar, molecules
Facilitated diffusion molecules go from
H-L
Types of Active transport
Direct, Indirect
Direct Transport
Chemical energy (ATP)
1 Protein
Indirect Transport
Ion Gradient
Usually 2 Part system
Parts of Indirect Transport
1 Protein uses ATP to setup Ion gradient
2nd Protein uses ion gradient as energy
Usually low ___ and High ___ in cell
Sodium, Potassium
__ Na out ___ K in
3; 2