Categorie: Tutti - meiosis - transcription - photosynthesis - atp

da Tyler Heng manca 1 anno

193

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The document delves into various biological processes and mechanisms central to cellular function and energy production. It covers transcription regulation, detailing the roles of activators, repressors, and enhancers in modulating gene expression levels.

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Meiosis

Meiosis l

Metaphase l
Chromosomes line up by pairs
Telophase l and Cytokinesis
Two haploid cells with two sister chromatids
Anaphase l
pairs separate
Prophase l
Chromosomes pair up and exchange segments

Crossing Over

exchange of genetic material between homologous pairs

Meiosis ll

Telophase ll and Cytokinesis
four haploid cells with two sister chromatids
Anaphase ll
Prophase ll
Metaphase ll

Cell Cycle

Mitotic phase

Mitosis
Phases of Mitosis

Telophase

Nuclear envelope reforms, chromosomes decondense, and spindle fibers disassemble.

Anaphase

Sister chromatids separate and are pulled to opposite poles of the cell by the spindle fibers.

Metaphase

Chromosomes align at the cell's equator, spindle fibers attach to kinetochores.

Prophase

Chromosomes condense and become visible, nuclear envelope breaks down.

Cytokinesis

Interphase

Phases of Interphase
G2 Phase

More Growth of cell and cell synthesizing of proteins for cell division

End of G2 completions

Nucleus contains one or more nucleoli

Nucleus with envelope seen

Each centrosome contains 2 centrioles

Two centrosomes formed by duplication

S Phase (DNA SYNTHESIS)

DNA Synthesis and DNA Replication occur resulting in duplication of chromosomes

G1 Phase

Growth of Cell and acquires materials for DNA synthesis

Translation

Termination

ribosomes reach top codon - UAG, UAA, or UGA
Site A accepts release factor - release factor breaks hydrolysis bond between P site tRNA and the last amino acid.

subunits break apart

Occurs in the nucleus of Eukaryotes

tRNA

A site - Aminoacyl tRNA binding site
E site - exit site
P site - peptidyl-tRNA binding site

Elongation

tRNA and amino acid
Translocation - ribosome translocates tRNA in A site to P site.

empty tRNA in P site is moved to E site to be released

mRNA with tRNAs bring the next codon to be translated into the A site.

codon recognition - anticodons bind to mRNA codons in A site.
peptide bond formed

removal of polypedtide from P site to attach to A site.

Initiation

small ribosomal subunit binds to mRNA
start codon - AUG (Met)
large subunit - rRNA with protein called initiation factors.

initiator tRNA in the P site.

A site available for tRNA with the next amino acid.

occurs in the cytosol of prokaryotes

Experiments Finding DNA

Hershey and Chase

Batch 2
DNA found
Batch 1
protein found

Messelon and Stahl Experiment

Medium containing N
intermediate medium
less dense medium

Fredrick Griffith Experiment

Bacterial strands
Heat killed S strand
S strand
R strand

alive mouse

Heat killed S strand + R strand

dead mouse

DNA Replication

DNA starts on the Origin of replication

Helicase , Topoisomerase and SSB begin to unwind the DNA into two different strands, creating a replication fork
Primase creates a strip of RNA primer so DNA Polymerase III can begin synthesizing the Leading and lagging strands

Lagging Strands go opposite of the leading strand

Also reffered to as Okazaki Fragments

Once synthesized, DNA polymerase I removes the RNA primer and replaces with DNA

Ligase binds the DNA together, completing the process

Leading strands go towards the replication fork, synthesizing 3' to 5'

Proteins used in DNA replication

DNA Polymerase III
Synthesizes new DNA strand by adding nucleotide to the 3' end of a pre exisitng DNA strand or off the RNA promer
DNA Polymerase I
Removes the RNA primer from the synthesized DNA strand
SSB proteins
Binds to the Single stranded DNA after Helicase unwids the double helix, making sure the DNA can be used as a template
Ligase
Binds the 3' end of the DNA that replaced the primer to the eading strand and "glues" together the Okazaki fragments from the lagginf strand
Helicase
Unwinds parental double helix at replication forks
Primase
Sets an RNA primer so DNA polymerase III can create the leading strands and lagging strands
Topoisomerase
Goes ahead of the helicase to releive "overwinding" of the DNA to ensure replications

lacZ, lacY, lacA

beta galactosidase, permease, beta transacetylase (respectively)

permease: allow the bacterial cell to take up sugar like lactose


beta-galactosidase: hydrolyzes lactose to produce galactose and glucose; glucose is preferred by bacteria cell


transacetylase: transfers an acetyl group from acetyl-CoA to beta-galactosides

RNAP

lacI gene

constitutive

negative regulation

positive regulation

operon

The operon comprises an operator (the on/off switch) followed by a cluster of functionally related genes.

lac operon

lactose present, glucose present
operator

When glucose is available in the bacterial cell, the operon will be off in which the repressor will bind to the operator. However, when the glucose is used completely, the operon turns on and the repressor will unbind and instead bind to allolactose. Beta-galactosidase, permease, and transacetylase will be translated from the mRNA to catabolize lactose, to make more glucose.

off and then on

lactose present, no glucose
adenyl cyclase

cAMP

CAP

promoter

allolactose

on
no lactose
repressor

operator

off

cluster of functionally related genes

Crystallin gene expressed due to activators binding enhancer

crystallin gene not expressed due to repressor

DNA bending protein

TATA box

RNA polymerase II

transcription factors

general

basal level transcription

enhancers

upstream or downstream of gene

activators

high level transcription

repressors

reduce high level transcription

Gene Regulation

in prokaryotes

in eukaryotes

combinatorial control of gene expression
lens cell (eye)

albumin gene not expressed due to repressor binding enhancer

Liver cell

albumin gene expressed due to activators

gene expression

DNA ligase

DNA polymerase II

nuclease

Nucleotide Excision Repair

thymine dimer

mutant type amino acids:Met Stop

mutant type mRNA: 5'- AUG UAG UUU GGU UAA-3'

wild type amino acids: wild type amino acids: Met Lys Phe Gly Stop

mutant type amino acids: Met Lys Phe Ser Stop

mutant type mRNA: 5'- AUG AAG UUU AGC UAA-3'

wild type amino acids: Met Lys Phe Gly Stop

mutant type amino acids: Met Lys Phe Gly Stop

wild type amino acids: Met Lys Phe Gly Stop

Mutations

frameshift

occurs in the event of 1 to 2 insertions or deletions of 1-2 nucleotides

sickle cell anemia

Nonsense

missense

wild type mRNA: 5' AUG AAG UUU GGC UAA

silent

mutant type mRNA: 5'- AUG AAG UUU GGU UAA- 3'
wild type mRNA: 5'-AUG AAG UUU GGC UAA- 3'

secrete enzymes such as

glycoprotein

polypeptide

vesicles

Protein transport

free ribosomes

signal sequence
SRP

signal peptidase

Once the the signal peptide is cleaved, the polypeptide is released from the bound ribosome and folds into final conformation

trans-face of golgi body

amylase, insulin, casein, albumin, and collagen

Amylase- a digestive enzyme found in lysosomes


insulin- a peptide hormone


casein- a milk protein


albumin- a serum protein


collagen- an extracellular matrix protein (gives plasma membrane increase tensile strength)

G3P

18 ATP

12 NADPH

NADP+ reductase

oxygen (O2)

ATP

NADPH

chloroplast

Photosynthesis

calvin cycle

two turns of the Calvin cycle are required to produce glucose

carbon fixation
rubisco

ribulose bisphosphate

Photorespiration

light reactions

stroma
thylakoid space
H+ ions

The hydrogen ions want to go with its chemical gradient in which ATP synthase allows for passage to the stroma, which has a low hydrogen ion concentration. ATP is produced when hydrogen ions pass through ATP synthase.

Non-cyclic flow of electrons
cyclic electron flow
thylakoid membrane
Photosystem II (P680)
photosystem I (P700)
chlorophyll

reduced

carbon dioxide

6CO2 +6H20 + Light ---> C6H12O6 + 6O2

Oxidized

water

Organic Molecules

lipids

fatty acids
glycerol

nucleotides

proteins

amino acids

carbohydrates

sugars

substrate level phosphorylation

ATP synthesis

Floating topic

Acetaldehyde

formed from the breakdown of ethanol

used for synthesis

NADH and FADH2 produced from glycolysis, pyruvate oxidation, and citric acid cycle

NAD+ Regeneration

bacteria pathway

oxidizing

2 ATP made in citric acid cycle

anaerobic conditions

aerobic conditions

Fermentation.

Lactic Acid
lactate

produced from exercise and metabolism

breaks down sugars

makes ATP

Alcohol
converts sugars to ethanol and carbon dioxide

3 Step Process

3.) ETC and Chemiosmosis
ATP Synthase
occurs in the inner membrane

protein complexes

Matrix of mitochondrion

Citric Acid Cycle

produces 6 NADH and 2 FADH2 after both acetyl CoA molecules enter and complete the cycle

1.)Glycolysis
pyruvate oxidation

Electron carrier NAD+ is reduced from the electrons from Pyruvate to produce NADH. A carbon is released from Pyruvate and produces carbon dioxide and a CoA molecule is joined with the remaining two carbons of Pyruvate

Pyruvate

Acetyl CoA

Acetyl CoA enters the citric acid cycle

Energy pay off phase

2 NADH produced

Energy investment phase

Glucose

Glucose 6-phosphate

Fructose 1,6-bisphosphate

Phospholipid Bilayer

Attatchment site

Selectively permeable

Fluidity

Hydrophobic Tail

Hydrophilic Head

Cell Membrane

Membrane Receptors

In target cells that receives the signal molecule.

ion channel receptor

Ligand gated ion channel receptor acts as a gate for ions to pass and change shape.

Tyrosine Kinase Receptor

when phosphate groups are added to tyrosines

Autophosphorylation

When each polypeptide on dimerization functions as a kinase so it takes phosphate groups from ATP and adds it to the other polypeptides.

protein kinases

enzymes that catalyze the transfer of phosphate groups from ATP to proteins

2 polypeptides

the polypeptides dimerize when a signal molecule is bound to them.

can add phosphate groups to something

Dimer

when a signal molecule binds it activating monomers to allow them to come together forming a dimer.

Interacting proteins

the activated tyrosine kinase receptor can now interact with other proteins for responses from the cells.

3 stages
3rd reception
2nd reception
1st reception
Membrane receptor

present on the plasma membrane

second messenger

needs help of the other molecules inside cells


They are small, nonprotein, water soluble molecules/ions that are used in signal transduction to relay a signal within a cell.


Synthesized from ATP using enzyme Adenylyl Cyclase

carbon monoxide

nitric oxide

Ca^2+

cGMP

cyclic AMP

Adenylyl Cyclase

converts the ATP to cAMP

Gene expression

mRNA are converted into proteins


can turn off some genes

Protein synthesis

Changes the activity of metabolic enzyme and open/close of ion channels

First messenger

Signal molecule is hydrophilic

G protein coupled receptor

Guanosine diphosphate, GDP, inactive form.

Guanosine triphosphate, GTP, active form

Binds GPCR

The single molecule binds to GPCR during reception

converting to GTP

G protein binds to the GPCR converting the GDP to GTP on the G protein

Activation of G protein

Happens when GTP binding

activate enzyme

the G protein can activate the enzyme

Intercellular receptors

present in the cytoplasm, in the nucleus

1. passes through the membrane

The signal molecule can bind if nonpolar or hydrophobic so it can pass the lipid bilayer and bind a receptor once inside the cell.

2. activation

The hormone binds to the receptor protein and activates it.

3. binds to specific genes

The hormone enters the nucleus and binds to specific genes.

4. protein acts as transcription factor

stimulating the transcription of the gene into mRNA

5. mRNA translated into protein

Cell Signaling

Nuclear envelope

Outer membrane

inner membrane

Nuclear pores

Functions of Membrane Protiens

Intercellular Joining

Signal Transduction

Binding to ECM

Enzymatic Activity

Cell-Cell Recognition

Transport

cell structures and functions

Eukaryotes

Cell Types
Plant

Cell Wall

Plasmodesmata

Animal

ECM

Cell junctions

Tight

Gap Junction

Desmosomes

Mitochondria
Named the powerhouse of a eukaryotic cell, as it generates ATP
Cell components
Cytoskeleton

Microfilaments

Actin

myosin

Intermidate Filaments

Microtubules

Tubulin

Nucleus

Chromatin

Nucleolus

Lysosomes

Vacuoles

Central

Contractile

Food

ADP

ATP

Hydrogen pump

Golgi apparatus

Vesicles

Endoplasmic reticulum

Rough Er

Smooth ER

Fats

Saturated

Unsaturated

Phospholipids

Steroids

Prokaryotes

Prokaryotes are split into Domain Archaea and Domain Bacterial

Domain Archaea

Extreme halophiles

Archaea that lives in highly saline environments

Extreme thermophiles

Archaea that thrives in very hot environments

Methanogens

Methanogens are Prokaryotic domain archaea cells that live in swamps and marshes to produce methane as a waste product.

metabolism

obligate aerobes

requires o2 for cell respiration

Facultative anaerobes

uses O2 when present, uses fermentation when O2 is not present.

obligate anaerobes

use of fermentation anaerobic respiration

Fimbriae

helps with attachment

DNA location

Ribosomes

protein synthesis takes place

Plasma membrane

membrane that enclosing the cytoplasm

cell wall

structure outside the plasma membrane

Glycocalyx

outer coating consists of a capsule of a slime layer

Flagella

movement structure

Heterotroph

Heterotrophs get carbon from organic compounds

Photoheterotroph
Chemoheterotroph

Chemotrophs get their energy from organic chemicals.

Autotroph

Autotrophs use inorganic carbon sources

Photoautotroph

phototrophs obtain energy from the light

Chemoautotroph

Chemotrophs get their energy from inorganic chemicals.

Domain Bacterial

Endospore

Endospores serve a purpose for survival under harsh environmental conditions.

Capsules/ slime layers

helps resists against phagocytosis and adherence to surfaces

peptidoglycan

cell wall filled with peptidoglycan. Helps bacteria with support, protects the cell, and maintains the shape.

pili

bacteria mating

Periplasmic Space

Periplasmic space contains hydrolytic enzymes and binding proteins for nutrient processing/ uptake.

Gas vacuole

Buoyancy of floating in aquatic environements

Plamid

DNA that is separate from the main bacterial chromosome

Nucleoid

DNA location

Intramolecular bonds

Ionic bonds

Non-polar covalent bonds
Polar covalent bonds

Connected through amino and carboxyl groups between mainchains

Transport Protiens

Carrier Proteins

Channel Proteins

Subtopic

Membrane Proteins

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2 NAD+, 2 NADH, 2 H+

Nucleic Acids

Phosphodiester bonds

Proteins

Protein Structures
Primary
Secondary
Tertiary
Quartenary
Amino Acids
Peptide bonds

Carbohydrates

Simple sugars (Monosaccharides)

Lipids

Functional Groups

Methyl (CH3)
Amino (NH3+)
Carboxyl (COO-)
Carbonyl (CO-)
Sulfhydrl
Hydroxyl (OH-)

Isomers and polymers

Enantiomers (Chirality)

g

Acids and bases

Water properties

f

Intermolecular interactions
Hydrogen bond

Ion dipole

Dipole-dipole

Hydrophiobic interactions

London dispersion