Cells
Biological Molecules
Carbohydrates
Monosaccharides
dehydration/condensation reaction
glycosidic bond/linkage
polysaccharide
Storage polysaccharide
Glycogen
extensively
branched
animals
Starch
Plants
alpha 1-4
glycosidic
linkages
Dextran
Structure polysaccharide
Cellulose
plant walls
beta 1-4
glycosidic
linkages
no branching
Chitin
Lipids
dehydration/condensation synthesis
fat molecule (triacylglycerol/triglyceride)
fatty acids
Saturated
Solid at room temp.
single bonds
Unsaturated
Isomers
Cis (causes bending)
Artificial Hydrogenation
transaturated fat
Trans
liquid at room temperature
glycerol
Phospholipids (amphipathic)
bilayer (in water)
hydrophobic tails
hydrophilic heads
polar
Proteins
Amino Acids
condensation/dehydration
hydrogen bonds
protein folding
primary structure
secondary structure
alpha helices
beta helices
tertiary structure
R Group
quaternary structure
denaturation
amino group
main chain
carboxyl group
unique R Group
Nonpolar
van der waals or hydrophobic
disulfide bond
Polar
Acidic
Basic
Functions: Enzymatic, Defensive, Storage,
Transport, Hormonal, Receptor, Structural &
Contractile and motor proteins
Nucleic Acids
nucleotides
condensation/dehydration
phosphodiester bond/linkage
DNA
transcription
mRNA
complementary base pairing
& antiparallel strands
double stranded
RNA
translation
5-Carbon sugar (pentose)
phosphate group
nucleosides
nitrogenous base
pyrines
Adenine & Guanine
pyrimidines
Cytosine & Thymine (DNA)
Uracil (RNA)
Three Domains of Life
Bacteria
Prokaryotes
endospores
Bacterial cell
gas vacuole
ribosomes
inclusion bodies
nucleoid
periplasmic space
cell wall
peptidoglycan
capsules and slime layer
circular chromosome
fimbriae & pili
flagella
membrane lipids
(unbranched hydrocarbons)
Archaea
extremophiles
extreme halophiles
extreme thermophiles
methanogens
anaerobes
Some Archaea Cell Components
Membrane lipids (some
branched hydrocarbons)
Circular chromosomes
RNA polymerase (several kinds)
Eukarya
Eukaryotes
Eukaryotic cell
Cytoskeleton
Microtubules
tubulin (alpha and beta)
Kinesin (motor proteins)
organelle movement
centrioles
centrosoles
helps chromosome movement
Microfilaments
actin
Myosin (motor protein)
Muscle Contraction
Cytosol
cytoplasmic streaming
Intermediate Filaments
several different proteins
(like keratins)
nuclear lamina
lamina
Nucleus (shape and stability)
Extracellular Components
Plant Cells
Cell Wall
Primary cell wall
Middle lamella
secondary cell wall
cell junctions
Plasmodesmata
Animal Cells
extracellular matrix (ECM)
Fibronectin
Integrins (membrane proteins)
Peptidoglycans
Collagen
cell junctions
Tight Junctions
Desmosomes
Gap Junctions
Flagella
motor
Some components
Membrane lipids
(unbranched hydrocarbon)
RNA polymerase
Methionine (Initiator amino
acid for protein synthesis)
Membrane-enclosed organelles
Nuclear Envelope
Cilia & Flagella
Dyneins (motor protein)
bending movement
ATP
Genetic information
DNA Structure
nucleotide
nitrogenous base (adenine,
guanine, cytosine, thymine)
hydrogen bonds
phosphate group
five-carbon sugar (deoxyribose)
phosphodiester bond
Cell Regulation
Mitosis
Eukariotic cells
Regulation of Gene Expression
Transcription factors
Promoter and Silencer region
RNA Processing Mechanisms
Chromatin Modification
Post Transcriptional Regulation
Translation Regulation
Protein Modification
cell cycle modification
Meiosis Regulation
Meiotic Spindle Formation
Cytokenisis
Mitosis Regulation
Mitotic Spindle formation
Enhancer and silencer region
Meiosis
Prokariotic Cells
Cell Division
DNA Replication
Semi-conservative model
Origin of Replication
enzymes & proteins
Helicase
separates the two
strands to form
replication bubble
Topoisomerase
helps relieve any strain
caused by unwinding of
the DNA
SSB
stabilizes the
unwound parental
strands
Primase
makes RNA primers
complementary to
the DNA parent strand
sequence
Replication bubble
Replication forks
leading strand
DNA polymerase III
synthesizes the leading
strand continuously 5' to 3'
sliding clamp
lagging strand
okazaki fragments
DNA polymerase I
removes the RNA
primer and replaces
with DNA nucleotides
Ligase
seals any gaps
(by connecting
nucleotides by
phosphodiester
linkages)
Gene Expression
Transcription
Prokaryotes
cytoplasm
Initiation
RNA polymerase (RNAP)
promotor
DNA strands unwind
initiates RNA synthesis
at start point (on template)
RNA polymerases (RNAP)
Elongation
RNA polymerase (RNAP)
new RNA nucleotides are
added from 5' to 3' end
mRNA
Termination
RNA polymerase (RNAP)
transcription termination site
transcription stops
Eukaryotes
nucleus
Initiation
transcription factors
RNA Polymerase II
Eukaryotic Promotor
(includes TATA box)
transcription initiation complex
pre mRNA
Termination
AAUAAA
modified G
nucleotide
(CAP)
translation
poly-A polymerase
polyA tail
mRNA stability
RNA Splicing
Spliceosomes
Exons
different mRNA & proteins
Introns
Translation
Prokaryotes
cytoplasm
Initiation
Initiation Factors
small ribosomal subunit
tRNA (carries fMet)
5' cap of mRNA
start codon (AUG)
translation initiation complex
Elongation
tRNA (carrying
correct amino acid)
A site
Peptidyl transferase
peptide bond
Translocation
Termination
stop codon (UAG, UAA, or UGA)
A site
release factor
GTP
Eukaryotes
cytoplasm
Initiation
small ribosomal subunit
tRNA (carries Met)
5' cap of mRNA
start codon (AUG)
translation initiation complex
Initiation Factors
Elongation
tRNA (carrying
correct amino acid)
A site
Peptidyl transferase
peptide bond
translocation
Termination
stop codon (UAG, UAA, or UGA)
A site
release factor
GTP
Protein Transport
protein synthesis (in cytosol)
organelles
mitochondria
nucleus
peroxisomes
chloroplast
(if a plant cell)
SRP (signal recognition particle)
ER
rough endoplasmic reticulum
vesicle
Golgi
membrane
secretion
(outside
of cell)
lysosyme
Plasma Membrane
Contains
Mosaic Plasma Membrane
Integral Proteins
Transmembrane Protein
Peripheral Proteins
Membrane Protein Functions: Transport, Enzymatic, Signal Transduction, Cell-cell recognition, Intercellular joining, Attachment to cytoskeleton and ECM
Phospholipid Bilayer
is comprised of
Serves as
Regulator of transport of substances via selective permeability
Doesn't allow ... across
Large, uncharged polar molecules
Ions
Types of transport across membranes
Passive
Down Concentration Gradient
Diffusion
Unfacilitated
Spreads from high concentration to low concentration until even distribution with no help
Osmosis
Water Balance of Cells
Tonicity
Isotonic
Solute concentration is same as inside of cell; no movement across membrane
Flaccid in plant cells
Normal in animal cells
Hypotonic
Osmoregulation
contractile vacuoles are used to pump excess water out of the cell
Solute concentration is less than inside of cell; cell loses water
Lysed in animal cells
Turgid (normal) in plant cells
Hypertonic
Solute concentration is greater than inside of cell; cell gains water
Plasmolyzed in plant cells
Shriveled in animal cells
Requires no energy
Bulk Transport
Transports larger molecules such as polysaccharides and proteins via vesicles
Active
Moves substances from low to high concentration
Cotransport
Occurs when active transport indirectly drives transport of other substances
Maintains concentration gradient
Proton Pump
Sodium-Potassium Pump
Uses phosphorylation with ATP to enable process
Uses electrogenic protein pump to transfer ions
Inside membrane
K+
Requires energy
Allows ... across
small nonpolar molecules
small uncharged polar molecules
Has
Membrane Fluidity w/Specific Temp
Can be affected by
Photosynthesis
Light Dependent reaction
Photosystem 2
Photolysis
Water Splitting
O2 Release
Photosystem 1
Nadph
Calvin Cycle
Carbon Fixation
Glucose Production
Specialized Cells
Lymphocytes
B Cells
particular antigen
T Cells
Macrophages
cell's immune response
Lipoproteins
cholesterol
HDL
LDL
Increased by Saturated and Trans fats
Main chain
main chain
Endomembrane system
Organelles
nuclear envelope
endoplasmic reticulum
golgi apparatus
lysosomes
phagocytosis
autophagy
plasma membrane
vacuoles
Food vacuoles
Contractile vacuoles
Central vacuoles
Endosymbiont Theory
Mitochondria & Chloroplasts
Eukaryotic Cell
Prokaryotic Cell
mitochondria
photosynthesis
Chloroplast
Symbiotic Relationship
High Temperature (Liquid Crystalline Phase)
Low Temperature (Gel Rigid Phase)
Facilitated
Transports substances that cannot diffuse on their own from high concentration to low concentration
Transports with the help of
Carrier Protein
Goes through changes in shape to translocate the solute-binding site across membrane
Channel Protein
Provides corridors to allow specific molecule/ion to cross the membrane
Outside membrane
H+
Na+
Generates voltage across membrane as membrane potential
Endocytosis
Transports larger molecules INSIDE of cell via...
Phagocytosis
The cell extends part of the membrane out (Pseudopodium)
Intakes nonspecific materials
Pinocytosis
Can be specialized
The cell intakes extracellular fluid
Exocytosis
Transports larger molecules OUTSIDE of cell
Receptor-Mediated Endocytosis
Acquire bulk quantities of specific substances using specific receptors that cluster to form a coated vesicle
Two types of cell signaling
Communicate
Signaling Parts
Signaling molecule
Molecule released by cell that is received by another cell
Receptor
Present in a target cell that receives signal molecule
Two types of receptors
Membrane receptor
Present in membrane
Receives molecules that cannot cross lipid bilayer
Stages of signaling
Reception
Transduction
Response
Phosphorylation Cascade
Uses Kinases and Phosphatases
signaling molecule binds to receptor
Relay molecule is activated and activates protein kinase 1
Active protein kinase 1 activates inactive protein kinase 2 by adding phosphate group
Active protein kinase 2 activates inactive protein which triggers...
Active protein causes cellular response
Nuclear Response
Last kinase from the phosphorylation cascade enters the nucleus
Phosphatases catalyze removal of phosphate groups making it inactive
All takes place in...
G-Protein linked receptor
Transmembrane Protein
G proteins such as Guanosine diphosphate (GDP) and Guanosine Triphosphate (GTP) are binded onto GCPR
When inactive, GDP is bounded
Signaling molecule binds onto the GPCR
GDP is replaced with GTP as the G protein is now active
G protein activates a nearby enzyme as it diffuses across the membrane
Phosphate group is removed, converting the GTP to GDP and moves the G protein back to the GCPR
Ion Channel receptor
Ligand-gated ion receptor remains closed
Signal molecules binds onto receptor
Gate opens which allows the movement of ions through the receptor via a channel
Ligand dissociates from receptor which closes the channel
Tyrosine kinase receptor
Begins as 2 inactive monomer peptides with 3 Tyrosine attached
Both peptides undergo dimerization to become active tyrosine-kinase regions
Autophosphorylation occurs until all tyrosine regions have a phosphate group
Autophosphorylation is when phosphate is taken from ATP to form ADP
Inactive relay proteins bind onto phosphate sites to trigger cellular responses
Each tyrosine can act as a kinase
A kinase adds phosphate groups
Needs help of second messenger
Used in signal transduction to relay signal within a cell
small, nonprotein, water-soluble molecules or ions
Cyclic AMP
AMP
enzyme phosphodiesterase
Intracellular receptor
Receives molecules that cross lipid bilayer
Present in cytoplasm
Physical contact
Use cell surface proteins to trigger response
Use junctions to directly connect the cytoplasm of adjacent cells
Local signaling
Long distance contact
Signal travels long distance to reach target cell
Hormonal Signaling
local contact
secreting cell releases signal
Synaptic Signaling
Paracrine signaling
Adenylyl cyclase
ATP
Inactive transcription factor is activated by the last kinase in the cascade
Inactive transcription factor binds onto DNA and activates gene expression
Electron Transport Chain
NADH Dehydrogenate
Nadh
Nad+
FMN
Fe-s Clusters
Coenzyme Q
Cytochrome bc1
Cytochrome c
Cytochrome c oxidase
Oxygen
H20
Succinate Dehydrogenate
FADH2
FAD