par Kylie Marie Il y a 1 année
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Eukaryotic mRNA's occur in the nucleus
Prokaryotic mRNA's occur in the cytoplasm (Transcription and Translation are coupled)
Occurs in the Nucleus
Done by RNA Polymerase 2
Proteins known as Transcription Factors are needed
Occurs in the Cytoplasm
Done by RNA Polymerase
No additional proteins are needed
Takes place in the Nucleus
Consists of multiple ORI bubbles that are fused together to speed up the process
Carried out by DNA polymerase alpha and beta
Takes place in the Cytoplasm
Consists of 1 ORI sequence
Carried out by DNA polymerase 1 and 3
The SRP binds to a receptor protein in the ER membrane, part of a protein complex that forms a pore
The SRP leaves, and polypeptide synthesis resumes, with simultaneous translocation across the membrane
The signal peptide is removed by signal peptidase (an enzyme in the receptor protein complex)
The rest of the completed polypeptide leaves the ribosome and folds into its final conformation through the addition of carbohydrate groups
A glycoprotein is formed
From the ER, the protein id shipped through a vesicle to the Golgi
The Golgi pitches off transport vesicles to transport the proteins to various locations
A transport vesicle can carry proteins to the plasma membrane for secretion
Examples of secreted proteins
ECM proteins: Collagen
Serum proteins: Albumin
Milk proteins: Casein
Peptide hormones: Insulin
Digestive enzymes: Amylase
Lysosomes, other type of specialized vesicle is available for fusion with another vesicle for digestion
same stop codon and is also a GTP driven process.
Stop codon UAG, UAA, or UGA. This is a GTP driven process
Once stop codon is reached in the A site, a release factor sits in the A site. The complex then disassociates and stops translation.
There is no such structure seen in prokaryotes
Post transcriptional modifications dont occur in prokaryotes
Eukaryotes have three types of RNA polymerases, I, II, and III, unlike prokaryotes
Eukaryotes form and initiation complex with the various transcription factors that dissociate after initiation is completed.
RNAs from eukaryotes undergo post-transcriptional modifications including: capping, polyadenylation, and splicing.
3) Termination: Once the polymerase reaches the terminator which is the sequence of DNA nucleotides that marks the end of the gene, it detaches from the DNA
This transfer of electrons down the electron transport chain lead to formation of ATP by photophosphorylation.
Output: 2 Acetyl CoA and 2 NADH
Net: 2 Acetyl CoA and 2 NADH
No ATP was made
Output: H2O, 26-28 ATP
Net: H2O and 26-28 ATP
The process to produce ATP was the coupling od chemiosmosis with the electron transport chain.
Key steps: ATP synthase the formation of ATP which is the endogenic process). ADP + Pi
Output: 2 pyruvate, 2NADH, 4ATP
Net: 2 pyruvate, 2 NADH, 2 ATP
The process to produce ATP is substrate level phosphorylation
Key steps: Used enzyme hexokinase to convert glucose to G6P which made phosphofructokinase.
Output: 6 NADH, 2FADH2, 2 ATP
Net: 6 NADH, 2 FADH2, 2 ATP
The process to produce ATP was at substrate level, phosphorylation
Key steps: Acetyl CoA+ forms citrate. And Isocitrate forms alpha ketoglutarate
Tyrosine kinase receptor
Ion channel receptor
G protein linked recept
A 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
The bound protein acts as a transcription facto, stimulating the transcription of the gene into mRNA
The mRNA is translated into a specific protein
Transcription factor stimulates transcription of a specific gene
Resulting mRNAs direct the synthesis of a particular protein
Cell responses can vary due to receptor types or intracellular proteins present
Cell may contract: decrease blood flow to digestive system
Cell may relax: increase blood flow to muscles
Eeleases glucose from cell: blood glucose level increases
cAMP activates a protein kinase, cAMP is converted to AMP by the enzyme phosphodiesterase
The activated protein Kinase will then activate another protein kinase with a phosphate group taken from ATP
Protein phosphatase catalyze the removal of phosphate groups from the proteins, protein is inactive again
Last kinase in the signal transduction cascade enters the nucleus and activates a transcription factor
Enzyme removes a phosphate group from G-Protein (Phosphatase)
GTP converts back to GDP, G-Protein is no longer active
transport protein that generates voltage across a membrane
Carrier proteins undergo a subtle change in shape that translocates the solute-binding site across the membrane
Voltage gated ion channel
Change in membrane potential allows ions to flow across the membrane through a channel
provide corridors or channels that allow a specific molecule or ion to cross the membrane.
Includes rRNA, mRNA, tRNA
Beta Glucose
Alpha Glucose
When the CO group is at the end of the chain
When the CO group is in the middle of the chain
Disaccharide
Dehydration/condensation reactions
Polysaccharides; Formed when 100 or more monosaccharides are bonded
Functions in cells
Structure
Beta glucose monomers
Cellulose; microfibrils in plant cell wall & insoluble fiber in humans
Connected through b1-4 glycosidic linkages
Storage
Alpha glucose monomers
Starch
Connected through a1-4 glycosidic linkages
Amylopectin
Amylose
Glycogen
Dextran
Transport of Substances
Storage of Amino Acids
Protection against disease
Accelerates chemical reactions
Support
Coordinates an Organisms activities
Movement
Cell's response to chemical stimuli
Charged R- groups
Basic R-groups
Side chain contains a complete positive charge and is Basic. All basic R-groups are hydrophilic.
Acidic R-groups
Side chain contains a complete negative charge and is Acidic. All acidic R- groups are hydrophilic.
Non-polar R-groups
Side chain contains a OH, SH, or NH group. NH can be classified as polar or non-polar. All polar R-groups are hydrophillic
Polar R-groups
Side chain contains a H, CH, or a carbon ring. NH can be classified as non-polar or polar. All non-polar R-groups are hydrophobic.
Polypeptides come together to form a functional protein. R-groups of both polypeptides interact.
Forms a Functional Protein
Polypeptide will fold through the interactions among R-groups
Folds into 3D shape
Main chain interactions among different amino acids, amino acids present determine secondary structure.
Beta Pleated Sheets
Alpha Helices
Amino acids are linked together through dehydration/condensation reactions
Polypeptide Chains
Creates cell cohesion and acute fraction of tissue cell sheets under tension.
A process or factory in which they receive proteins from ER
Produces ATP for cell survival and functioning . The mitochondria is known as the powerhouse of the cell.
Contain digestive enzymes to break down toxic materials in the cell.
It is made of a protein called Actin. Microfilaments also assist with cell movement. Microfilaments have other functions which include cell motility, changes in cell structure etc.
Cytoskeleton
Also assist in cells shape, and cell movement.
Central Vacuoles: Are found in many plant cells. And they serve as a repository for inorganic ions, like potassium and chloride.
Contractile Vacuoles: Are formed when many freshwater protist and pump excess water out of cells.
Food vacuoles: Are formed when cells take food or other particles
Helps cell maintain shape. Involves chromosome segregation and mechanical support, organization of the cytoplasm.
Lysosomes are membrane-bound organelles packed with enzymes. They also use their hydrolysis enzymes to recycle the cell's own organic material.
Smooth Endoplasmic
Synthesis lipids and metabolizes carbohydrates. It also detoxifies drugs and poisons, and stores calcium ions. Smooth ER also lacks ribosomes attached to it.
Rough endoplasmic reticulum
Produces proteins for the rest of the cell to function. This process is called protein synthesis. Rough ER is also studded with ribosomes.
Helps cell attach to surfaces in its own environment
Helps maintain cell shape. It also prevents the cell from bursting when theres too much water.
Regulates growth and replication. It also controls bacterias activity and reproduction.
Separated from chromosomal DNA so it can replicate independently.
Is adhesive and allows itself to attach to surfaces.
Allows cell movement
Bacteria contains peptidoglycan
Protects bacterial cells from environmental stress. Also helps give the cell wall structural strength, protecting the cell wall.
Unsaturated fats:
A fatty acid with one or more double bonds
Saturated fats:
A fatty acid without a double bond
The structure of fatty acids would be a hydrocarbon chain with about 15 carbons with a carboxyl group attached at one end
To make a fat molecule glycerol has to be linked with three fatty acids.
The structure of glycerol is the three-carbon chain molecule with each carbon-containing a hydroxyl group and all the other open bonds containing hydrogen
