DNA and Cell Structures

Junctions between Cells

Cadherins

Notes:

  • cadherins are the proteins and adhesion molecules that connect adjacent epithelial cells at the points of desmosomes
    --> form the anchor between adjacent epithelial cells
  • note that cadherin proteins need Ca++ in order for them to bind each other
    --> think cadherin = Calcium
  • intracellularly cadherins attach to desmosomes of cells
  • extracellularly cadherins bind to other cadherins of other epithelial cells with the help of calcium

dropped image link

dropped image link

DNA replication and
Protein Synthesis

Transcription

  • transcribe DNA --> mRNA

Post-transcriptional modifications of RNA
--> hnRNA --> pre-mRNA --> mature mRNA

  • 3 major steps of postranscription modification
  • 5' Cap
  • 3' Poly A Tail
  • Splicing out of introns
    --> splicosome = collection of snRPs and proteins

post-transcriptional modification

dropped image link

Genetic *Mutations

Genetic Mutation Types

*Missense mutations
-

*Nonsense mutations

  • missense mutation that actually inserts a STOP codon
    --> early breakage of the protein

*Frameshift mutations

  • note always check for not having MULTIPLES of 3
    --> if there is a multiple of 3 added, then you CANNOT have a frameshift mutation

*Silent mutations

  • mutations that only have a point mutation in an AA
  • they lead to NO change in the AA inserted

dropped image link

Allelic Heterogeneity

Notes:

  • note that whenever talking about ___ heterogeneity, this means there is difference = hetero- within that object that results in the same phenotype
    --> the exception is phenotypic heterogeneity ofcourse where it means different phenotypes from the different mutations on the same gene
  • in allelic heterogeneity we are talking about possibly different mutations within the same allele, but they all manifest as the same phenotype
  • in genetic heterogeneity we are talking about possibly different gene mutations within different genes, but they all manifest as the same phenotype
  • in phenotypic heterogeneity we are talking about different phenotypes arising from the same gene undergoing different mutations
  • note in the above that polygenic disease means that a disease is cause by defects in multiple other genes
    --> best example is T2 DM which is clearly hereditary, but so many different genes are involved that we don't know of

dropped image link

dropped image link

Case example:

Insulin

Preproinsulin and
Insulin Generation

Notes:

  • note that preproinsulin has an N-terminal signaling sequence that is read to direct it to the rough ER for final translation
  • translation of the preproinsulin mRNA actually starts in the cytosol as the mRNA is moving out from the nucleus
  • the preproinsulin mRNA is being translated in the cytosol when the DNA Pol A reaches the signal sequence at the N-terminus
    --> this immediately stops the translation and signals for SRPs = signal recognition particles to transport it to the rough ER for further translation
  • preproinsulin then cleaved into proinsulin, which forms loop structure inside the rough ER
    --> made of A and B chain polypeptides and with a C-peptide loop at the end
  • sent to golgi in transport vessicle, further packaging in the Golgi and again buds off into a secretory vesicle
  • once in a secretory vessicle and heading towards the plasma membrane for transport outside the cell, the C-peptide is cleaved from the proinsulin molecule
    --> in the secretory vessicle you now have C-peptide and insulin that are released from the cell and into circulation

dropped image link

dropped image link

dropped image link

Example:

dropped image link

dropped image link

dropped image link

*Lab Techniques

Radiolabelled Assays

  • fix antibodies to an assay
  • put antigens in that are radiolabelled
  • meaasure the radioactivity to see how much antigen is bound to the antibodies
  • can be used to compare whether proteins/antigens have common epitopes

Example:

Notes:

  • in this case the antigens X and Y are put into the same assay
  • Antigen X is added and creates radioactivity
  • since the radioactivity stays the same as Antigen Y is added, this means that it does NOT bind to the assay and hence has no common epitopes as Antigen X does

Notes:

  • 3 main post-transcriptional modifications
  • 5' methyl-guanosine capping
    --> helps stabilize the 5' end of mRNA from being degraded in the cytosol
  • 3' Poly-A tail capping
    --> helps stabilize the 3' end of mRNA from being degraded in the cytosol
  • removal of introns from the mRNA by snRNPs = small nuclear ribonucleotide proteins
    --> exons are "actual DNA", "introns are out"

dropped image link

Poly A tail and complement

Notes:

  • note always think of the 3 major post transcriptional changes to mRNA and their complements

dropped image link

dropped image link

dropped image link

dropped image link

dropped image link

dropped image link

Tight Junctions

Blood Brain Barrier

  • Blood BB is possible through Tight Junctions

Blood BB and Tight Junctions

Clinical Case

Notes:

  • note the main reason why the Blood BB is able to keep molecules out is through tight junctions
  • these tight junctions are also supported by astrocytes cells that surround the cappilaries
  • there are no fenestrations = opennings in the Blood BB capillaries either

dropped image link

dropped image link

dropped image link

dropped image link

Gap Junctions

Notes:

  • note that in preparation for delivery nearing the end of a pregnancy, myometrial cells start to express connexin proteins and oxytocin
  • connexin proteins are needed in the myometrium for gap junctions betweent he muscle cells so they can forcefully contract
  • oxytocin receptors are needed since oxytocin from the posterior pituitary gland initiates contractions

Case example:

dropped image link

dropped image link

Hemi's AdDES integrin to ANCHORS

  • anchor junctions are made by:
    Adherin junctions --> cadherin
    desmosomes --> cadherins + others
    hemidesmosomes --> integrin

connexin CONNEX the GAPS
gap junction --> connexin



Tight junctions OCCLUDE water soluble drugs from the Blood BB
tight junctions --> occludin and claudins

dropped image link

Cellular Proteins / Structures

Cell transport

  • vessicles
  • microtubules
  • kinesein and dyneins

*Organelles

Microtubules

Kinesins and Dyneins

Kinesin Transport Example

Clinical Case

Notes:

  • note that kinesins transport secretory vessicles towards the growing end = positive end of microtubules = AWAY from the centre of the cell and towards the periphery
    --> classic example would be ACh NTs that are brought to loading zones at the cell membrane near Ca++ channels to be ready for release

dropped image link

dropped image link

"DYNesins DINE with MINE at HOME,
Kinesins are KIND and POSITIVE and dine away"


  • Dynesins are proteins that transport vessicles along microtubules
    --> towards negative (-) end
    --> towards the cell centre
  • Kinesins are proteins that transport vessicles along microtubules
    --> towards positive + end
    --> towards the periphery

dropped image link

dropped image link

Protein Synthesis Codons Overview

  • reading DNA
  • reading mRNA
  • building AA with tRNA

Start and Stop Codons


START Codons: Are U Going? (to start?)

  • AUG

STOP Codons: U Are Annoying!! ... U Go Away!! ... U Are Gone!!

  • UAA
  • UGA
  • UAG

DNA Structure

*Telomeres

  • telomerase adds TTAGGG repeats at the 3' ends of DNA
    --> these end pieces = TAGs are telomeres
  • prevent them from being degraded
  • this is mostly done in the stem cells of the body since they need much longer telomeres
  • other mature cells of the body have shorter telomeres
    --> when a telomere reaches a certain short length it signals for apoptosis of that cell

*Collagen Protein

  • most abundant protein in the human body
  • major component of connective tissue + extracellular matrix
  • 4 subtypes of collagen

4 Types of Collagen

  • to remember 4 types of collagen --> be COLLEGIATE and spell them out

type 1 --> ONE --> bONE
--> bone, tendons, skin



type 2 --> TWO --> carTWOlage
--> type 2 collagen makes up cartilage
--> especially hyaline cartilage


type 3 --> 3 D --> ThreE D --> Ehlor Danslos and others
--> Ehlor Danslos affect synthesis of type 3 collagen
--> blood vessels, also uterus and fetal tissue
--> NOTE that MARFANS is NOT COLLAGEN like Ehlors even though they have similar presentations
--> MARFANS is extracellular fibrillin scaffolding for elastin


type 4 --> Four --> FLOOR = basement membrane
--> any disease with basement membrane
--> GBM = Goodpasture Syndrome with antibodies to the renal GBM and pulmonary BM

MI and collagen 1 deposition scarring post MI

Notes:

  • note the period 2 wks --> 2 months post MI your heart starts laying down fibrotic scar tissue on the damage myocytes of the heart
  • recall that myocytes can't regenerate so your body has to replace them with collagen type 1 scarring
  • type 1 collagen is the same that is in bones, tendons, think the starting materials for tissue

Example:

dropped image link

dropped image link

Cartilage

dropped image link

Skeletal Muscle

*Sarcomere Structures

  • see other note under musculoskeletal

SNoW DRoP BLOT tests

  • DNA
  • RNA
  • Proteins

Western Blot

  • protein identification

Western Blot example 1

Notes:

Example:

dropped image link

dropped image link

Amino Acids and their Derivatives

Arginine

  • Arginine makes NO through eNOS
  • eNOS = endothelial NO synthase
  • responsible for vasodilation of blood vessels in response to
    --> Bradykinin, sub p, etc.

Arginine --> NO synthesis --> vasodilation

Notes:

  • note that

Clinical Case

dropped image link

dropped image link

dropped image link

dropped image link

Tyrosine

  • used to make Monoamines
    --> Tyrant wants MONO control

*Types of Receptors

  • receptors are broadly either cell surface receptors or intracellular receptors
  • note MOST horomones are lipophillic and bind inside the cell
    --> exceptions

Intra vs Outer Cell receptors

Intra vs Outer Cell receptors - Hormones example

Case presentation:

Notes:

  • note that most hormones are lipophilic and bind inside the cell
  • think of hormones as being POWERFUL, but they take time for them to work and LASTING
    --> hence bind INSIDE the cell
    --> transcription changes genes
  • things like insulin and glycogen bind outside the cell

dropped image link

dropped image link

Notes:

  • most horomes bind intracellular
  • Exceptions of Hormones that bind outside the cell:
  • GH = Growth Hormone
    --> JAK-STAT pathway
    --> think of Silver fox teacher
  • parathyroid hormone = PTH
    --> think PTH has tight control on calcium so has to be quick and bind outside

dropped image link

dropped image link

Histone Proteins

  • recall nucleosome cores have 8 proteins
  • H2a, H2b, H3, H4 x 2
  • H1s are are on their own = 1
    --> outside the core, H1 holds together linker DNA

Telomeres and telomerase in Malignancy

Case example:

Notes:

  • note

dropped image link

dropped image link

dropped image link

*RNA

  • subtypes
  • location made, etc.

Synthesis and Function of 3 main RNA subtypes

  • remember RNA 123

dropped image link

  • RNA subbtypes RNA 123 makes RMA

R / 1 = RNA 1 make ribosomes
M / 2 = RNA 2 makes mRNA
A / 3 = RNA 3 make the AA builder = tRNA

RNA case

  • note that ribosomal rRNA is made and assembled in the nucleolus
  • note that basophilic means "stains dark"
    --> how they described nucleolus

Notes:

  • note that

Clinical Case

dropped image link

dropped image link

dropped image link

Western Blot example 1

Example:

Notes:

dropped image link

dropped image link

dropped image link

*Translation by rRNA and tRNA

  • mRNA to polypeptides (amino acid sequences --> folded into proteins)

transfer RNA = *tRNA

  • carries AAs tot he ribosome to add to the polypeptide chain

dropped image link

ribosomal RNA = *rRNA

  • 60S and 40S
  • releasing factors bind to the ribosome and casue the release of the polypeptide when the mRNA reaches one of the 3 STOP codons
    --> UAA
    --> UGA
    --> UAG

*Ribosomes - Cytosol Ribosomes vs. RER Ribosomes

  • RER ribosomes
    --> send proteins for cell membrane, secretory, nucleus (NOT the nucloelus), Golgi and lysosomes

Modified Translation during Apoptosis

  • use of the IRES = internal ribosomal entry site
  • this starts translation
  • instead of the normal recognition of the 5'prime cap

Notes:

  • note that in apoptosis, can't use the normal recognition of the 5'prime cap
  • in normal translation, the small unit of the ribosome binds to the 5' cap
  • the 5' cap is found by eIFs = eukaryotic initiation factors
  • instead during apoptosis, these eIFs are degraded and need to use the IRES = internal ribosomal entry site to start translation
  • note also here that normally during eukaryotic translation, there are not multiple open reading frames
    --> there are multiple reading frames in prokaryotes, but NOT eukaryotes
    --> not sure why I thought this was true for eukaryotes?

dropped image link

dropped image link

Clinical Case

Reading mRNA: Translation

  • mRNA read in the 5' to 3' direction
  • opposite to DNA reading

Reading mRNA Practical Example

  • mRNA is read in the 5' --> 3' direction
  • opposite to DNA reading
  • think the AAs need to match the original DNA so the mRNA is read in the opposite direction to the DNA

Notes:

  • here first look for the stop codons
  • remember to read mRNA in the 5' to 3' direction
  • find UAA UGA UAG
  • then it is asking for the codon before this
  • make sure to put the 3' and 5' in the right place, they switch them sometimes

Clinical Case

dropped image link

dropped image link

dropped image link

dropped image link

dropped image link

Enzymes

  • Helicase = stairCASE unwinder
  • ssBPs = single strand binding proteins
    --> holds the unwound DNA open
  • gyrase = topoisomerase II = stops supercoiling
  • RNA Primase = lays the initial primer for the DNA Pol 3 on both leading and lagging strands
    --> note that RNA primase is the ONLY enzyme in DNA replication that makes RNA and not DNA
    --> doesn't need to be DNA as it is removed by DNA Pol 1 anyways
  • DNA Pol III = think DNA read in 3' --> 5' direction = DNA POL 3 at
    --> starts after primase lays first
    --> reads DNA in 3' --> 5'
    --> makes DNA in 5' --> 3' and proof reading 3' --> 5'
    --> proof reads in BACKWARDS direction ONLY
    --> can't take out bits and add at the same time like DNA POL 1
  • DNA Pol 1 = the ONE DNA Pol that has both 5' --> 3' synthesis and exonuclease in the same direction
    (DNA pol 3 ONLY has backwards = 3'-->5' exonuclease backwards proof reading)

Pre Replication Fork Factors for Transcription

  • Transcription Enhancers = several base pair upstream ? how many
  • CAT TATA TAT = initiating and TATA box promotor base pair upstream ? how many
    --> right before the genes to be encoded

Transcription Enhancer

  • located even more upstream from the CAAT initiater sequence
  • creates a loop in the DNA after DNA POL has started and makes it go faster

dropped image link

CAAT and TATA box

  • Song = "CATS comin down the track... "
    .- "TATA TAT"
  • CAAT = initiating sequence for DNA transcription
  • TATA box = promoter region after CAAT

CAAT and TATA box example

Notes:

  • note that

Clinical Case

dropped image link

dropped image link

dropped image link

DNA Coding Strand = Sense strand
vs Template Strand

dropped image link

Notes:

  • coding strand = sense strand
    --> identical to mRNA
  • template strand
    --> is the template for RNA to copy as a template

Practical Transcription - Practise Qs

  • coding strand / sense strand = actual DNA that is the same as the mRNA made
    --> remember the protein is the important thing and ultimate goal
    unwinder
  • template strand / nonsense strand = template DNA for the mRNA to be made from
    --> think it would not make the protein
    --> it is nonsense

dropped image link

dropped image link

Notes:

  • note that the exonuclease and DNA/mRNA synthesis 5' --> 3' always refers to the strand being made
  • ex - DNA is read in the 3' --> 5' direction, so DNA Pol 3 has 5' --> 3' direction synthesis

dropped image link

dropped image link

dropped image link

dropped image link

COLL A GEN synthesis

  • "COLL A GEN" = CAG rule of 3s
  • C = Vitamin C / Scurvy needed in collagen synthesis
  • A = alpha chains = 3 of them
  • G = GLYCENE rule of 3 in collagen
  • Collagen Rule of 3s = 1/3 AAs in collagen are GLYCINE

dropped image link

dropped image link

*Home

DNA Damage and *Repair

dropped image link

Base Excision Repair

  • GEL PLease
  • glycosylase , endonuclease, lyase, polymerase, lygase
  • this is usually for switching out wrong individual bases, etc
    --> not quite the same as dimers in UV damage

*Modifications of DNA

  • methylation
    --> CpG = MUTED
    --> Histones = MAY be MUTED
  • acetylation = ACTIVE

dropped image link

*Acetylation of DNA

  • Activates DNA
  • deactelyation = deactivates DNA
    --> seen in HD

Pathophys of HD

  • CAG repeats --> cause deacetylation --> trasncription silencing

dropped image link

dropped image link

dropped image link

*Mitochondria

Mitochondria
example

Example:

Notes:

  • note when looking for mitochondria on electron microscope, first identify is there is a nucleus and a nucleosome present, then find the mitochondria which have lines that make up their matrix

dropped image link

dropped image link

dropped image link

*Peroxisomes

  • PER - OXIDATION = fatty acid oxidation that can't be done by the mitochondria
    --> VLCFA = very long chain fatty acid oxidation in the peroxisome

*Nucleosome

  • contained in the nucleus
  • main site for rRNA = ribosomal RNA synthesis and assembly before they are sent out
  • nucleus has 2 main jobs
    --> keep DNA + make ribosomes to make the proteins

Mitochondria
example

Example:

Notes:

  • note

dropped image link

dropped image link

dropped image link

*Peroxisome Disorders

  • can't break down VLCFA = very long chain fatty acid oxidation in the peroxisome

dropped image link

dropped image link

NUCLEAR pot transcription modification of pre mRNA

  • 3 major steps of postranscription modification

*5' Cap

  • 1/3 nuclear step of Post-transcriptional mRNA modification
  • stops the mRNA degraded in the nucleus

*3' Poly A Tail

  • 2/3 nuclear step of pre mRNA modification
  • stops the mRNA degraded in the cytoplasm
    --> keep losing the 3' tail
    --> this makes sense as you need a STOP at the end of RNA, this is more important

*Splicing out of introns

  • LASTS = 3/3 nuclear step of pre mRNA modification

dropped image link

*Introns and exons

  • EXONS = Actual mRNA that get EXPRESS
  • INTRON = just there to INTERRUPT the ACTUAL mRNA

dropped image link

*PCR
(Polymerase Chain Reaction)

*ELISA kits

ELISA kits

  • Enzyme-linked immunosorbent Assay (direct / indirect)
  • for identifying antibodies and proteins

dropped image link

Example:

dropped image link

Notes:

  • to identify whether someone has been exposed to a certain virus and has antibodies / immunoglobulins to that virus
  • step 1 - line wells with viral antigen and add patient serum to the wells
    --> if they have antibodies to the virus they will bind to the antigens of the well
  • step 2 - wash the plate
    --> this removes any other proteins etc. that have not binded to the specific antigens
  • step 3 - add the substrate-modifying E = EL part of ELISA
    --> the enzyme that is linked to a specific substrate that will activate the enzyme is key to the whole process of the ELISA kit
    --> the enzyme here is attached to an anti-human immunoglobulin antibody
    --> this attaches to the patient's human antibody
  • step 4 wash again
  • step 5 - add the substrate to the wells to activate the enzyme
  • the degree of colour change or whatever the enzyme does will tell you how much of the antibody is present in the well
    --> the substrate linked enzyme = substrate-EL is usually peroxidase

dropped image link

Notes:

  • "PCR = 95.7 is a TAQy station that PRIMES DNA for NEW TRIAL songs"
  • PCR 95.7
    --> 95 degrees C = denature the original
    --> 55 degrees C = cools down for primer to attach to the needed sequence
    --> 72 degrees C = TAQ polymerase elongates the new DNA strand
  • TAQy station
    --> TAQ polymerase = thermos aquatic polymerase is able to work at high temps of 72 degrees
  • PRIME DNA for NEW TRIALS
    --> 3 ingredients needed for PCR are: primer, DNA original, nucleotide triphosphates

dropped image link

dropped image link

*Agglutination inhibition tests

  • AI tests have antigens to something like beta hCG
  • add urine/solution to the AI fluid
  • then you add latex coated in hCG (or what yu are testing for)
  • agglutination happens with latex coated = negative result
    --> since there was no hCG before
  • NO agglutination with latex coated = positive result
    --> since there is hCG present from before

dropped image link

Triple alpha helix in CAG COLL - A - GEN

  • CAG COLL - A - GEN
    --> C = Vitamin C neded for collagen synthesis
    --> A = alpha triple helices
    --> G = glycine every 3 AAs gives the flexible structure for collagen / with prolines in between that give the rigidity needed
  • note the triple helix structure is ONLY in the PROCOLLAGEN polypeptide that has to be cleaved
  • PROCOLLAGEN is then cleaved into collagen fibrils that all CROSS LINKED to each other by LYSYL OXIDASE
    --> think of collagen as being strong like a bacterial cell wall because it has individual building blocks = collagen fibrils that are crosslinked to gether to make it strong
    --> just like in bacterial cell wall the D-ALA - D ALA are crosslinked to make a strong bacterial cell wall

dropped image link

dropped image link

*Transcription factors

  • leucine zipper transcription factor

*leucine zipper - Transcription factors

  • leucine zipper transcription factor

dropped image link

dropped image link

*Transport across membranes

  • passive diffusion vs active protein carrier transport

dropped image link

dropped image link

Clinical Cases

Clinical Case

Clinical Case

Notes:

  • note that

Reading mRNA Practical Example

  • mRNA is read in the 5' --> 3' direction
  • opposite to DNA reading
  • think the AAs need to match the original DNA so the mRNA is read in the opposite direction to the DNA

Clinical Case

Notes:

  • note that tRNA has a CCA end at the 3' end
    --> CCA has OH group attached to it where the AAs bind
  • tRNA is held together by hydrogen bonds of complement sequences
  • has a DAVENPORT clover LOOP structure
  • D = D loop
  • A = anticodon loop
  • V = small V loop
    T = T loop

dropped image link

dropped image link

Charged vs. Uncharged tRNA

  • Uncharged tRNA goes out to bind to AAs
  • once tRNA binds to AAs it becomes charged and can bind to the A site of the Ribosome for giving its AA

dropped image link

8releasing factors

  • bind to the ribosome and casue the release of the polypeptide when the mRNA reaches one of the 3 STOP codons
    --> UAA
    --> UGA
    --> UAG

dropped image link

dropped image link

*Flanking region

  • note you need to know the nucleotide sequence of the 2 flanking regions on either side of the exon or gene you want to copy and amplify
  • the flanking region = DNA primer binding region

dropped image link

Clinical Cases

Clinical Case

Clinical Case

Notes:

  • note that

dropped image link

dropped image link

Mechanics of splicing

  • "Get U!" -- INTRONS -- "All GONE!"
    --> GU -- INTRONS -- AG
  • GU marks the 5' end of introns to START the cut by snRNPs and the splicosome
    --> snRNPs = small nuclear ribonucleic Proteins
  • AG marks the 3' end of introns to END the cut by snRNPs and the splicosome

dropped image link

dropped image link

*Methylation of DNA

  • Methylation of cytosine or adenosine in DNA
    --> "makes DNA MUTE"
    --> expecially methylation of CpG islands in DNA
  • Methylation of Histones though
    --> "MAY make DNA MUTE or it MAY not"
    --> this is the exception to the rule

dropped image link

dropped image link

*FISH = Flourescant In Situ Hybridization

  • this is a lab technique for highlighting chromosome abnormalities
    --> this is the even smaller version of the SNW DRP lab tests

Telomeres and telomerase in Malignancy

dropped image link

Clinical Cases

Clinical Case

Clinical Case

Notes:

  • note that

Telomeres and telomerase in Malignancy

Notes:

  • note that only germline cells have telomerase naturally since they are dividing so often and need telomerase to make and replace the telomere
  • other than this telomerase activity is pathogenic and is present in 90% of cancers since telomeres normally signal through the p53 tumor supressor gene to start apoptosis when DNA has undergone too many divisions

Case example:

dropped image link

dropped image link

dropped image link

*Telomerase enzyme

  • telomerase adds TTAGGG repeats at the 3' ends of DNA
    --> these end pieces = TAGs are telomeres
  • prevent them from being degraded
  • this is mostly done in the stem cells of the body since they need much longer telomeres
  • other mature cells of the body have shorter telomeres
    --> when a telomere reaches a certain short length it signals for apoptosis of that cell

dropped image link

dropped image link

Clinical Cases

Clinical Case

Clinical Case

Notes:

  • note that

dropped image link

*Lyonization = X inactivation

  • in each cell of the body of a female, one of the X chromosomes is randomly chosen for inactivation
    --> becomes a Barr Body
    --> done by heavy Methylation = MUTED DNA

dropped image link

dropped image link

Nucleotide Excision Repair

  • similar to BASE excision and GEL PLease
  • glycosylase , endonuclease, lyase, polymerase, lygase
  • key is there is no Glycosylase since you are not taking out and switching the base
  • this is from UV damage and repairs dimerized pyrimidines
    --> thymine and cytosine

dropped image link

dropped image link

CYTOPLASM *PBODY modification

  • use microRNA to degrade or change the mRNA

dropped image link

*Endoplasmic Reticulums and Golgi Apparatus
-

dropped image link

*Rough ER

  • has ribosomes and makes proteins

dropped image link

*Smooth ER

  • has NO ribsomes and is used for making steroid hormones
  • thus high in androgen making cells, gonads, etc.

dropped image link

*Golgi Apparatus

  • has no ribosomes and is used to packege proteins into secretory vessicles for transport from the cell

dropped image link