Unit 2 Flashcards
What is happening during G0? What stage comes after?
Where the special cells are performing their day to day routine.
What comes after is When mitogen made introduced to the cell and interphase begins at G1
What is happening @ G1?
What comes after this stage?
G1 is when the cell if growing, protein synthesis and organelle duplication/ production are taking place
G1 is a stage of interphase. After is the S stage
What is happening during the S stage?
What comes after?
This is where the DNA is replicated and the proteins are synthesized.
It is part of the interphase within G1. Next is G2
What is happening during G2?
What comes after?
G2 is a time for more! Protein synthesis and DNA begins to condense
Goes G0, G1, S , G2 now prophase
What is the largest portion of the cell cycle? Where parental cell is growing, preparing for division, synthesizing necessary proteins and duplicating all DNA molecules?
Interphase
What part of the DNA, has the needs to make one or more functional proteins?
Gene
Define transcription factors
Regulatory proteins bind to DNA at a promoter region that will either active or inactive a gene expression
What is the process when DNA base sequence is used to make a complementary piece of RNA specifically called pre-mRNA
Transcription
What part of the cell allows DNA to be copied into RNA
Nucleus
What enzyme separates two strands of DNA double helix at a specific gene then synthesis a completar y strand of RNA
RNA polymerase
What specific RNA is a complementary to a gene coded by DNA and then ultimately read by ribosomes to create the protein
mRNA
Define introns
A no coding segment of a immature or! Pre-mRNA molecules that are removed during alternative splicing to convert premRNA into mature m mRNA
What extra cellular fluid suspends erythrocytes, leukocytes and thrombocytes
Plasma
What is the extra cellular fluid that surrounds body tissues cells?
Interstitial fluid
What fluid is inside all body cells where the nucleus, organelles and inclusions are suspended?
Intracelular fluid
What defines the passive movement of molecules from high to lower contraction or certain molecules?
Diffusion
Define osmosis
Passive movement of water across the plasma memebrane to maintain osmotic equilibrium
There are two types of membrane transporters. What type directly links extraceullular and intracelular compartments. Only allow passive movement of ions
Channel proteins
Type of membrane transporter that bind substrates on one side of plasma membrane and transport them through to the other side. Are either active or passive transport
Carrier proteins
Whats it called when molecules move through a plasma membrane through concentration gradient and net transport stop when the concentrations are equal on both sides of the membrane
Facilitated diffusion
What are exons?
During mRNA processing these sections of pre-mENA are kept then spliced together to form mature mRNA
What type of membrane transporters moves molecules against their concentration gradient and ATP is needed as an energy source
Active transport
What is the role of translation?
Translation is when the mature mRNA directs the assembly of amino acids into a polypeptide or protein
What type of channels or pores spend most of their time with their gate open? This allows ions to move back and forth the membrane without regulation
Open
What type of channels spend most of the time closed? They can be opened under specific conditions then allow the movement of ions across the plasma membrane?
Gated channels
What channels will change support when the electrical state of the cell reaches a specific level?
Voltage-gated
What mature mRNA is read by this organelle to create a new protein chain
Ribosomes
What channels must bind an intracelular or extracellular signal molecules to become open
Chemically - gated
What is codon
A triplet of mature mRNA that code for a specific amino acid
Define a anti port
Where a protein moves two or more types of solutes in opposite directions
What type of molecules delivers a specific amino acid to a ribosome during translation in order to be attached to a growing polypeptide of protein
tRNA
What type of carrier protein moves two or more types of solutes in the same direction
Symport
Define a anticodon
A triplet of nucleotide based that bind a complementary trio of based on the mature mRNA molecules
What does post translational modification do?
It’s a process within the lumen of the rough ER where proteins must undergo further development since they are not fully mature after development. Proteins will fold into complex shapes, may be split by enzymes or have various chemical groups added
What class of enzymes break down mRNA that is no longer needed since they (mRNA ) do not last forever
Ribonucleases
What cycles is a smaller portion of the cell cycle where the duplicated parental chromosomes are separated and passed to new daughter cells and the cytoplasm of the parental cell divides
Mitosis
Define membrane potential
The electrical gradient between the intracelular fluid and extracellular fluid
What phase is the sub phase of interphase? A cell wil duplicate its DNA molecules so that each daughter cells gets a full complement of genetic instructions
S phase
In regard to nerve and muscle cells, is the inside of the cell more negatively or positively charged compared to the outside
Negatively
There are specific points in a cell cycle where the cell may determine if it’s DNA is healthy and if has enough resources to ÷ successfully. What are these points called?
Check points
Cl- ions diffuse through the ion channel the inside of the cell will be come negatively charged than be fore
Hyper polarized
If sodium ions diffuse through a ion channel the inside of the cell become what? To be more positively charged than before
Depolarized
What is apoptosis?
When a cell determines that it cannot fix an error in its DNA & cannot complete its cell cycle successfully it will self destruct
If Na+ channels close & k+ channels open the charge inside the cell would return its its resting state known as becoming
Repolarized
What are chemical signals?
A term to describe molecules secreting by a cell into the extra cellular fluid then decreed by specialized receptors elsewhere in the body
Define a target cell
Cell that has specialized receptor proteins to detect the presence of chemical signals
What phase describes the cells in our body that are currently resting and performing their specialized function. They’re not dividing nor preparing to ÷ at all
G0 phase
What are gap junctions?
These junctions allow cell-to-cell communication. Allow electrical and chemical signals. They are proteins channels that create cytoplasmic bridges between adjacent cells
What is the procress that describes cells communicating on the surface molecules on one cell membrane binding to a membrane receptor on another cell. An example are cell adhesion molecules
Contact - dependent signaling
What are sister chromatid
Two identical condensed DNA molecules that are held together by a centromere and make a “x-shape” structure
What is a paracrine signal
A chemical that acts on a cell in the immediate vicinity of the cell that secreted the signal
What are chromatid
One molecule of DNA that has been condensed into “log-like” structure prior to cell division
What is a autocrine signal
A chemical signal that acts on the same cell that secreted it
What DNA molecule is not fully condensed but loosely wrapped around small proteins call “histones”. Look like beads on a string
Chromatin
What is a chemical signal that is secreted by specialized cells (endocrine glands) into the blood and is then distributed all over the body by circulation
Hormone
What sub phase of mitosis sister chromatids split apart. Allowing spindle fibers to pull individual chromatids towards opposite poles of the cell
Anaphase
What the hell is a neuro hormone
A neuron that secreted a signal molecule into the blood stream for distribution
What sub phase of mitosis describes the individual chromatids arriving at opposite poles of the dividing cell and new nuclei form around them
Telophase
What is a neurotransmitter? Different from a neurohormone?
A neuron secreted a signal molecule that binds to a receptor on a nearby neuron and that event has a rapid and short lasting effect on the target cell.
What sub phase of most paid describes the sister chromatids fully condensed and visible. Spindle fibers begin to extend from opposite poles of the cell and the nucleus is dissolved by the end of this phase
Prophase
What is a neuromodulator
A neuron secrets a signal molecule that binds to receptors on a nearby neuron and that even has slow or prolonged effect on a target cell
What sub phase of mistosis describe the sister chromatids attach to spindle fibers and all line up at the center of the cell in a single file line
Metaphase
What is cytokine
A type of signal molecule that can be produced by almost all cells, travel through the blood and is particularly important in the immune system communication
What is cytokinesis
Dividing of the cell and its cytoplasm during mitosis. It starts in anaphase and finishes in telophase
Define signal transduction
Transmission of information from one side of the membrane to the other using membrane proteins
Whats it called with information is transmitted from one side of the membrane to the other using membrane proteins
Signal transduction
What kind of receptor allow signal molecules to bind and cause change within the intracelular cytoskeleton
Integrin receptors
What kind of receptor will activate an intracelular enzyme to which it is physically attached
Receptor enzyme
What kind of receptor has 7 membrane spanning regions. When it bind a signal molecule it can either open a ion channel or alter the activity of intracelular enzymes like phsopholipase C
G-protein coupled receptor
What kind of receptor binds a ligand that will either open or close the channel and change the flow of ions across the membrane
Receptor channel
What is diffusion faster? (4 things)
-Along high concentration gradients
-Over shorter distance
-At high temperatures
-For smaller molecules
What makes simple diffusion faster?
-The membrane surface area is larger
- the membrane is thinner
- concentration gradient is larger
- the membrane is more permeable to the molecule
During simple diffusion the membrane permeability to a molecule depends on what?(3things)
-The molecules lipid solubility
- the molecules size
- lipid membrane is thin
What “thing on a cell “maintains the chemical and electrical disequilibrium for proper cell function ?
Membrane transporter
What specialized channels allows water to move freely through the membrane
Aquaporins
What substance cannot move freely through the cell Membrane? What do they need in order to facilitate their movement through the membrane?
Ions & polar molecules. They need membrane transporters
What are channel proteins? What uses them?
Fluid filled tunnel like passageways that only accept ions and water. They only move depending on electrochemical concentration.
Describe open channels and their alternate names? What do the allow?
Called leak channels or pores. Are open most of the time
They allow free flow of substance via facilitated diffusion through them into or out of cell when open
What are gated channels? What is their function?
Gated channels need a trigger to open or close. They regulate movement of ions into or out of a cell based on a cells needs at a given movement
What are the 3 types of gated channel proteins
- Voltage gated
- Chemically gated
- Mechanically gated
What stimulates that’s
change the permeability of a voltage-gated channel protein
Changing permeability in response to a change in the cells membrane potential
What is the stimulus that change the per mail it’s of a chemically gated channel protein?
Change permeability in response to a chemical stimulus (ligands bind to receptor)
What is the stimulus for mechanically gated channel?
Pressure or temperature changes
What do monovalente cation channels allow to enter and leave cells
They allow Na+ to enter and k+ to leave the cell
Define transplant maximum
When a protein mediated transport reaches a point of saturation
How did secondary active transport get called secondary?
Does not (use ATP) So it depends on ion concentration gradient made by / from the primary active transport. Uses one solute to move down the concentration gradient and at least one solute is moving against its concentration gradient.
What type of transport is handled by carrier proteins? Is moved at least one solute down the concentration gradient. The other moves against the concentration gradient as well powered by ion concentration gradients
Secondary active transport
What type of transport is handlers by carrier proteins & moves all solutes against the concentration gradient by using ATP
Primary active transport
What type of transport requires energy from ATP & moves substances against a concentration gradient from low to high
Active transport
What type of transport doesn’t need ATP and move substances down a concentration gradient from high to low
Passive transport
Name the three passive transport
Osmosis, simple diffusion and facilitated diffusion
What are they called? Small fragments of DNA produced on the lagging strand during DNA replication that are later joined by DNA ligase to form a complete strand?
Okazaki fragment
What is the role of DNA polymerase?
It is a enzyme that inserts and binds free nucleotides that match the DNA parents strand based
What is the enzyme that breaks hydrogen bonds between complentary based to unzip double helix?
DNA helicase
What two enzymes replicate by unzipping and duplicated each DNA parent strand?
DNA helicase & DNA polymerases
After modification in the rough ER where do protein to next?
Golgi complex for sorting and packaging
What is a splicosome
An enzyme used to edit mRNA
What is a snRNPS?
Group of small nuclear ribonucleoproteins that combine to form a splicosome
What is the role of RNA polymerase?
- unzips DNA to show the correct gene
- catalyze the reaction from ribonucleotides to a pre-mRNA strand
What enzymes creates pre-mRNA for the DNA template
RNA polymerase
Where does post transitional modification occur?
Within the lumen of the rough ER for only some proteins
How did primary active transport get its name?
Energy “ATP” is being used at the site of transport or exchange . Not use an ion concentration gradient. Moves all solutes against their concentration gradient
What are the three types of active transport?
Primary, secondary and vesicular
Is the plasma membrane polar or non polar
Polar
Is the inside of a cell negatively or positively charged?
Negatively
What is the HCO3- mean and most seen in or out of a cell
It mean bicarbonate and more concentrated in the cell
What is simple diffusion? What are they permeable to?
Some lipids : steroid hormones , fatty acids
No polar gases : o2 & co2
Simple diffusion is these molecules or ions moving through the bilateral without any membrane transporters.
What is facilitated diffusion? What is it permeable to?
• Ions and polar molecules such as Na+ , k+ , amino acids, glucose
• used membranes like channels or carrier proteins
Facilitated diffusion use membrane transport proteins like channels and carrier proteins
What is a monovalente cation channel
A type of membrane transport (channel) where Na + will enter and K+ is leaving
Does glucose need a carrier protein or channel protein or even a membrane transport?
Yes it needs a carrier protein. Called glucose transport
What is happening to solutes during facilitated diffusion in carrier proportions?
All solutes move down a concentration gradient
What do carrier proteins move?
Charged or polar or large molecules through the membrane
Why would chloride be diffusing out of a channel protein?
Electrical chemical gradient pulls it out
What two things will affect active transport to work?
• ATP
• Ion concentration gradient (to moves substrates from low to high level across the membrane
What is the sodium postassium pump?
A carrier protein that use ATP to move all solutes against their concentration gradient. Hold 3 sodium for two potassium
What is a sodium glucose transporter
A term to describe a secondary active transport. Carrier protein that moves a a sodium against a concentration gradient and glucose down its concentration gradient
Define facilities diffusion
A channel or carrier protein that moves all solutes down their concentration gradient
What is receptor mediated endocytosis
• ligand bind to a membrane transported
• this stimulates clayhrin coated pit
• endocytosis
• vesicle loses Claritin coat
• receptors and ligands separate
• ligands transport to lysosome or golgi for processing
• transport vesicle with receptors moves to the cell membrane
• transport vesicle and cell membrane fuse and are recycle
What is transcytosis?
Describes solutes travel across a cell using both endocytosis and exocystosis
Define transcytosis
Solutes travel across a cell using both endo & exocytosis
What is a voltmeter?
A machine to register voltage in a cell ICF or ECF
What works to maintain resting potential at all times?
ATPase pumps or ion pumps
Which channels open during depolarization?
Influx of both ca 2+ & Na+
What channels open during repolarization
Cl- influx and k+ efflux
What channels open to lead to hyper polarization
K+ efflux and cl- infflux
What is the point of hyper polarization?
It helps make a special cell delayed for a certain amount of time . Even less active than normal.
What is a GLUT transporter?
A carrier protein, of facilitated diffusion for glucose
What forms of physiological signal take?
Electrical and chemical signals
What type of cells create the two different signal to communicate info?
Signal generators or neurons, endocrine cells or immune cells
What type cells respond to physiological signal
Targets cells
What are gap junctions
Form a direct cytoplasmic connections between cells called connexins. They transfer chemical and electrical signals
What is a connexins
A physical connection by membrane complexes spanning proteins
What is a contact dependent signaling?
They require interaction between membrane molecules on two cells . they use CAMs . They transfer signals both directions
What is CAMs?
Cell adhesion molecules. Surface molecules on one binds to protein receptors on the other
What are some polar molecules? Can they go through the plasma membrane?
Proteins, amino acids, nucleotide
What are some non polar molecules?
Steroid Hormones,water and some gases co2 and 02 . They can pass through the plasma membrane no problem.
What are the steps of communication pathway?
Signal molecules-> (bind to)-> intracelular signal molecules —> (alter) —> target proteins —> ( create) —> response
What
What does “Signal amplification “do
To take a process of a small signal and making it big .
Define intercellular signal cascades
Step of intracellular signal transduction pathway form a cascade . A chemical acctivates the next and so on until the final change in a cells function is achieved.
What are the three main ways to trigger a cell response?
• Phphorylation
• Modulation of intracellular calcium binding protein
• modulation of ion channels in the plasma membrane
Process for tyrosine kinase of receptor enzymes
- Signal molecule binds to receptor
- Change in shape in function for receptor and enzyme —> binding does appears on enzyme
- Tyrosine kinase take ATP + protein and causes a active protein + ADP
Substrates : ATP + protein
- Chan he in cell function
Give example of amplifier enzymes
Adenylyl cyclase , guanylyl cyclase, phospholipase C
How does adenylyl cyclase be a receptor enzyme
Adenylyl cyclase converts of ATP to cyclic adenosine monophate (cAMP)
Substrates : ATP
products : bunch of cAMP
1. Signal molecules bind to receptor
2. Change ins shape/function for receptor and enzyme
3. Lots of ATP attaches to binding site and makes a lot of cAMP
4. cAMP stimulates protein workers
5. Proteins workers stimulates cell function
How does guanylyl cyclase convert GTP (guanosine triphosphate to cyclic guanosine monophate (cGMP)
- Signal molecule bind to receptor protein
- Receptor enzyme change /function
- G-protein loses affinity for GDP a then GTP attaches to receptor enzyme and makes cGMP
- Stimulate protein workers
- Stimulate cell function
What are second messenger? And examples?
cGMP & cAMP they spread the message
What is a GPCR
A gene protein coupled receptor alters enzyme activity on the intracellular side of the membrane or open ion channels in the membrane
Step for GPCR: Adenylyl cyclase -pathway
- Enzyme bind to receptor
- Receptor protein + Gprotein change shape/function
3.lose affinity for GDP & gain affinity for GTP - GPCR slide over to Adenylyl cyclase
- Then same step for AC RECEPTOR ENZYME
Protein worker is protein kinase A
What’s is GTP
guanine triphosphate
What is GDP
Guanosine diphosphate
Steps GPCR : the phospholipase C pathway
Steps 1 -4 are the same for adeneylyl cyclase but for phospholipase C
5. Pulls a phospholipid and rips it into two part
6 . Inositol triphosphate ( polar) and diayglycerol (non polar) are made
7. Smooth ER needs a inositol triphosphate to release calcium
8. Calcium binding proteins will stimulate cell function
9. Diaylgllycerol stimulate protein kinase
10. ATP + inactive protein goes into protein kinase. Protein kinase makes ADP + active protein
11. Products from protein kinase cause change in cell function
what do alpha receptors do ?
needs epinephrine to help cause vaso-constriction
what do beta receptors do ?
needs epinephrine to help cause vaso-dilation
in modulation to cell-to-cell communication , what is up-regulation
the increase of receptors through proteinsynthesis
in modulation to cell- to -cell communication what is down regulation
decrease the # of receptors also related to drug intolereance
in regard to cell-to-cell communication what is desentizing
to decrease the affinity to a signal molecule
Can man made molecules like toxins, drugs pathogens affect antogonist or agonist receptor that alter homeostasis
yes
what are the two ways intergrating center usually react ?
tonic or antgonistic pathways
define tonic control
tonic control wil either increase the stimulation or decrease the signal . always relased by a neuron
define antagonistic control pathway
description of when a organ ( like the heart) that is intervated by 2 different efferant pathways. the 2 efferent pathways have different signal molecules . one increase activity and other other decreases activity of the effector
what receptor is is the fastest ?
channel receptors .
