The Cells
Eukaryotes
Plant Cells
Nucleus
Basis of activity and growth
genes, and structures that have hereditary information
DNA
Nucleic acid
Nucleotides
phosphodiester linkages
Pentose
Nitrogenous base
DNA from any species of any organism should have a 1:1 stoichiometric ratio of purine and pyrimidine bases
A = T and G = C
Phosphate
sets of 3 are used to lay down amino acids to form a polypeptide and that secret code is the Codon Chart
DNA Replication
Tested if DNA can transfer between bacterias by injecting them into a mouse and seeing if it survived or not. Mixed heat killed smooth pathogenic cells with rough nonpathogenic cells.
Resulted in heat killed smooth cells transferring its DNA to the rough cells, turning them into smooth cells.
transcription
mRNA is produced by RNA polymerase II with the help of transcription factors and binds to promoter
template strand
mRNA
at the start codon, moves downstream
from 3" to 5", and generating mRNA from 5' to 3'
leaves nucleus
Translation in cytoplasm
mRNA is translated to form proteins
nontemplate
RNA Polymerase II
promoter
the 2 strands
template strand and start making RNA transcription in 5' to 3' direction
pre-mRNA
A Eukaryotic promoter commonly includes a TATA box about 25 nucleotides upstream from the transcriptional start point
Several transcription factors, one recognizing the TATA box, must bind to the RNA before RNA polymerase II can bind in the correct position and orientation
Additional transcription factors bind to the DNA along with RNA polymerase II, forming the transcription initiation complex.
RNA Polymerase II then unwinds the DNA double helix and the RNA synthesis begins at the start point on them template
5' cap is made due to guanine nucleotide w/ 3 phosphate and a poly A tail. It is added as a protector
AAUAAA, is called the poly-A site
When the Pre-mRNA is made, the AAUAAA is present in an enzyme called Ribonuclease. It comes along and breaks the phosphodiester bond, releasing the pre-mRNA .
an enzyme called poly A polymerase will add 100-200 As at the 3' end
RNA Processing
introns, exons, 5' cap, 3' polyA tail
exons, 5' cap and 3' poly A tail
RNA splicing; the process of removing introns
through Spliceosome; is a complex of proteins and RNA that does the splitting
to make different proteins called Alternate slicing
Pre-mRNA and mRNA
bind to proximal
control elements
regulate eukaryotic
gene expression
bind to enhancer
sequences
Transfer their DNA into bacteria cells. This reprograms the cell to produce more bacteriophages.
The Hershey-Chase Experiments
Two batches of bacteriophages were grown. One with 32S(associated with proteins) and the other with 32P(associated with DNA). Each were then allowed to infect bacteria cells and were put in a centrifuge.
The pellet produced from both were examined and the 32S was found in the liquid, while 32P was found in the pellet. This concludes that the genetic material transferred is in the DNA.
Helicase separates
ds DNA into 2 parent strands,
forming a replication bubble
at ORI
SSB
Topoisomerase
multiple ORIs
makes RNA primers
complementary to parent strand
to add nucleotide monomers to
3' end of primer through phosphodiester bonds
Leading strand that
requires 1 primer
primers removed and replaced
with DNA by DNA polymerase I
ligase
Mitosis
Somatic cells
Prophase
Separates the cells into
two identical daughter cells
Metaphase
Chromosomes condense and
divide the cell
Anaphase
Forms two identical
daughter cells
Telophase
End of mitosis
Nuclear membranes reform
Lagging strand that
requires multiple primers
Okazaki fragments
1 ORI
Intracellular Receptors
Receptors is inside the cell
Steroid Hormones
The Steroid hormone aldosterone passes through the plasma membrane
Aldosterone binds to a receptor protein in the cytoplasm activating it
The hormone receptor complex enters the nucleus and binds to specific genes
l
The mRNA is translated into a specific protein
binding of hormone w/ receptor causes receptor to be activated and changes its shape
through nuclear pores, binds the DNA and RNA is made through transcription, proteins are made through translation
by making proteins
because a signal molecule came in contact with the receptor
Ribosome
Proteins
primary
amino end and carboxyl end
Peptide Bonds
secondary
alpha helices, and beta pleated sheets
Hydrogen Bonds
Bonds between polar covalent
molecules that contain hydrogen
attached to F,O, or N
tertiary
polypeptide folds through R groups to form three dimensional shape
Depends on the R group
Acidic and Basic R groups are going to form Ionic Bonds
Polar and Nonpolar are going to form hydrophobic and hydrophilic bonds
Different types of R groups
Non-Polar
Electrons are
shared evenly
between atoms
Having H or CH or Carbon rings
Inside of membrane or not on surface
Hydrophobic
Polar
Electrons are shared
unevenly btwn atoms
Having OH, SH, or NH groups
Outside of membrane or surface
Hydrophilic
Having a tendency to mix with, dissolve in, or be wetted by water
Acidic
pH < 7, negatively charged
Basic
pH > 7, positively charged
quaternary
interchain interactions
Noncovalent bonds between complementary surface hydrophobic and hydrophilic regions on polypeptide subunits
Denaturation
translation occurs
mRNA and initiator tRNA
adheres to start codon
to complete translation initiation complex
enters ribosome and carries an amino acid
covalently bound to Met
using peptidyl transferase
leaves ribosome, and shifts over for the next tRNA
to the 1st two and this process continues all the way down mRNA
polypeptide chain will grow
stop codon is reached
the completed polypeptide swims away
folding and modification
golgi through vesicles
plasma membrane
rough ER or lysosomes
mitochondria, chloroplasts,
peroxisomes, or nucleus
recognize signal peptide
and transport complex to ER
where synthesis continues
cleaved by signal peptidase
Golgi
Secrete cell productions (proteins and lipids)
Mitochondria
Generates energy in form of ATP
potential
stored energy
kinetic
associated with motion of molecules or objects
Plasmodesmata
facilitate exchange of signaling molecules b/t neighboring cells
Chloroplasts
site of photosynthesis
Converts energy of sunlight to chemical energy stored in sugar molecules
the calvin cycle produces sugar from CO2 with the hep of NADPH and ATP produced by the light reactions
6CO2+6H2O+light energy = C6H12O6+6O2
to convert radiant energy from the sun into chemical energy that can be used for food
Pathway that consumes energy to build complex molecules from simpler ones
cells of the mesophyll, interior tissue of the leaf
30-40 chloroplasts
Peroxisome
helps with oxidation reactions
metabolism, detoxification, and signaling
Central Vacuole
Waste dump to keep the cell in shape
Cell Wall
Maintains cell shape
Cellulose
Carbohydrate
Monosaccharides
Glycosidic linkages
Covalent bond
Structure
Chitin
Storage
Glycogen
Starch
Prokaryote
Bacteria
Cell Wall
Petidoglycan
Protects bacterial cells from environmental stress
Protects the cell from lysis and gives structure
Break down nutrients
Flagella
Used for cell movement in some prokaryotes
Fimbriae
Attachment structure on some prokaryotes
Archaea
Nucleoid
Area of cell that holds genetic material.
Cell Wall
phytohormone
biosynthesis
Cytoplasm
Transcription occurs in prokaryotes
RNA Polymerase (RNAP)
DNA to pick the template strand (the parent strand)
Daughter strands
separate the 2 strands
template strand to start RNA transcription in 5' to 3' direction
mRNA
starts transcription
mRNA is translated to protein
Step 1. Initiation
After RNA polymerase binds to the promoter, the DNA strand unwinds, and the polymerase initiates RNA synthesis at the start point on the template strand
Step 2. Elongation
The polymerase moves downstream, unwinding the DNA and elongating the RNA transcript 5' to 3'. in the wake of transcription, the DNA strands re-form double helix
Step 3. Termination
Eventually the RNA transcript is released, and the polymerase detaches from the DNA
5' cap and poly a tail, and introns
Translation occurs here for Eukaryotes and Prokaryotes
Animal Cells
ER
Smooth
stores and synthesizes lipids
Rough
produce proteins
cytoskeleton
Microfilaments
Microtubules
chromosome movement,
organelle movement
Maintains cell shape
Cell motility
Intermediate filaments
Anchors nucleus,
forms nuclear lamina
Centrosome
Regulates cell motility
Lysosomes
Breaks down biomolecules
cell junctions
tight junctions
Prevents movements
desmosomes
form stable adhesive junctions b/t cells
gap junctions
Allows for movement between cells
Plasma Membrane
Protects the interior of cell by allowing certain substances into cell and other substances out; Help support the cell and help maintain shape
Different modes of transport used to transport materials
Active Transport
Requires energy in the form of ATP. Moves from a low to high concentration to transport through cell membrane
Can take place anywhere in the cell
Sodium Potassium Pump
maintains the internal concentration of potassium ions [K+] higher than that in the surrounding medium concentration of sodium ions [Na+]
Used in the cellular membranes
r
Transport of small molecules that directly uses ATP as an energy source
Cellular Respiration
Step 1: Glycolysis
C6H12O6 + 6O2 → 6CO2 + 6H2O
Pathway that releases energy by breaking complex molecules into simpler compounds
Secondary Active Transport
Transport of small molecules that uses an established electrochemical gradient to power the movement
Bulk
Endocytosis-taking
something into cell
Phagocytosis
when a cell engulfs large food particles/other cells by extending part of its membrane out
Pinocytosis
when the cell takes in extracellular fluid from outside in vesicles
Receptor-mediated
endocytosis
specialized type of pinocytosis that enables the cell to acquire bulk quantities of specific substances
Move very large molecules across a membrane using vesicles
Proteins and Carbohydrates
Exocytosis - contents
leaving the cell
Ions moving across
their concentration gradient
Passive Transport
No energy required, moves from high to low concentration
diffusion
tendency for molecules of any substance to spread out evenly into available space as a result of thermal motion
osmosis
diffusion of free water across a selectively permeable membrane
Facilitator
Allow diffusion process to take place in membranes that are made up of glycoprotein
cotransport
occurs when active transport of a solute indirectly drives transport of other substances
phospholipids
Lipids
chemical messengers,
energy storage
Fatty acids
Saturated
Animals
Unsaturated
Plants
Double covalent bonds
Short Tail length
Membrane Fluidity
nervous system
myelin sheaths
nonpolar
molecules
hydrophobic
interactions
Membrane Fluidity
Help Cell membranes and membranes surrounding organelles to be flexible and allows for vesicle formation and enables substances to enter or exit a cell through bulk transport
Membrane Receptor
G-Protein linked receptor
G-protein couple receptor changed shape and binds to and activates G-protein by changing it's shape
G-protein leaves receptor to bind to and activates an enzyme called Adenylyl Cyclase
Adenylyl Cyclase converts ATP to cAMP
Triggers a phosphorylation cascade
Activates transcription factor for gene expression
cAMP is going to bind to a kinase (1,2,3)
1st kinase is activated, gets to rely molecules and activate it; it gets a kinase so it will take a phosphate group and add to the next protein that is also a kinase. Now its active; it will take a phosphate group from ATP and add to 3rd kinase; and repeats; hence why it is called a Phosphorylation Cascade
To amplify the signal
As each kinase is activating the next, they themselves will be switched off due to cost of phosphate group due to phosphatase
cAMP
One Phosphate is used to make cAMP
c
removes Phosphate and convert back to GDP
inactive
Signal Molecule binds to receptor again
Phosphatase; it can remove a phosphate group
Tyrosine kinase receptor
Two receptor tyrosine kinase proteins form a dimer after activation
Unphosphorylated dimer --> Phosphorylated dimer
Active relay proteins produce cellular response
Each polypeptide are kinases: it takes phosphate from ATP and adds to Tyt; takes phosphate from ATP and adds to polypeptide at Tyrosine. When all 6 Tyrosine gets phosphate groups. It is now fully activated receptor. We call it Phosphorylated because it has phosphate groups added. Once fully activated, rely protein binds and cell response
Protein kinases
Enzymes that catalyze the transfer of phosphate groups from ATP to proteins
Ion channel receptor
Channel remains closed until ligand binds to the receptor
Channel opens but only a specific ion is able to flow through the channel.
Channel closes and ions are no longer able to flow.
On the post synaptic cell membrane