BIOLOGY UNIT 7

Central Dogma

describes the process by which DNA codes for proteins, which determine the traits that all organisms exhibit

why dose the DNA live in the nucleus and stays there

• Too precious! We want to keep it safe inside the nucleus

transcription

The process of turning DNA into mRNA

Process of transcription

• mRNA makes a copy by matching RNA base pairs to DNA base pairs

• An enzyme called RNA polymerase “reads” the DNA and builds mRNA (polymerizes RNA)

RNA polymerase

“reads” the DNA and builds mRNA (polymerizes RNA)

 promoter regions

sections that encourage RNA polymerase to bind to DNA and start reading

Start and stop codons tell the RNA polymerase where to start and stop coding

DNA ( binding)

• C binds to G

• A binds to T

Translation

The process of turning mRNA into protein

Translation ( process)

• mRNA is “read” by ribosomes and another type of RNA called transfer RNA (tRNA)

• tRNA reads 3 base pairs of mRNA at a time

  • Every 3 base pairs codes for 1 amino acid

codons

a Divided DNA sequence into sections of 3 base pairs

Start and stop codons

tell the RNA polymerase where to start and stop coding (building mRNA)

how do humans let viruses within their cells

they bind to receptors in our cell membrane that allow them to enter the cell ( they trick us)

Vacines

• Vaccines introduce an antigen to our bodies that then resukts in our cells making antibodies that deffend it against pathogens

antigen

• any substance that your immune system identifies as foreign and harmful

• found on pathogens

antibodies

• proteins created by white blood cells to fight against pathogens

pathogen

any infectious agent ( virusis)

mRNA (binding)

• C —> G

• A—> U

• T— > A

tRNA

• reads mRNA to create proteins

• reads 3 base pairs of mRNA to make an amino acid

mRNA

sends a message of genetic instructions

RNA polymerase

reads DNA and builds mRNA

Green florescent protein (GFP)

• allows humans to actually see what happens within the cell better , by marking and observing multiple proteins at a time

• like a highlighter

genes

portions of DNA

• can help code for protiens

Protien Sthynisis

• the process of making protiens

• DNA to Protiens

Anticodon

• attached to trna that bonds to the codons on mRNA

peptide bond

boninfd amino acids together

rRNA

• ribosonal RNA

• Are what ribosomes are made up of

White blood cells

cells that fight against pathogens

B & T cells

WBC’s that target specififc pathogenss

Memory B & T Cells

B & T cells that remeber pathogeos

• they multiply quickly when the have idenified the pathogens so they can efficantly fight against them

Virus v. Bacteria

• viruses are not alive, cant reproduce “ normally” ( they need a host cell because they don’t have ribosomes to read their RNA) , no organelles ( ribosomes), no cell wall

• Bacterias are everthing viruss are not ( reproduce through binary fission and they have DNA & RNA)

 Live Vaccines

• Use a weakened form of a pathogen

• our bodies respond by making anti bodies

• produce long lasting effects ( because our bodies can already recognize the pathogen)

• not sutable for weak immune system( pregnant women)

Inactivated Vaccines

• Use a dead/inactivated pathogen

• don’t have long lasting effects ( more shots may be needed)

• safer for weak immune systems

– Recombinant Subunit

• Use only part of a pathogen,

• not as strong as a live vacines, sometimes needing booster shots for continued immunity

• safe for most people

mRNA ( vaccenices)

• uses mRNA

• the mRNA codes for spicific Protiens / antibodies that fight pathogens

• safe for most people

How Mutations occur

• errors in DNA replication

• errors transcription

• exposure to mutagens

Mutagens

physical, chemical, or biological factors that can directly or indirectly increase the likelihood of DNA damage/mutations

Point Mutations

when one base pair is changed but the number of base pairs doesn’t change

• Silent ( Same , 1st )

• Nonsense ( stop, horrablie)

• Missense ( diffrent, 2nd)

Frameshift Mutations

When a base pair change has happened that runins the entire mRNA’s genetic code

• insertion ( +)

• deletion ( - )

Gene

Section of DNA that codes for specific traits ( eye color)

Allele

Variations of the gene that can exist (

Mutation

Change of DNA that can result in a different allele

Genotype

The genetic makeup of an individual

•  homozygous dom. ,  homozygous rec. , heterozygous)

Phenotype

Observable characteristics

Codominance

• traits that have multiple dominant alleles

• When both of these dominant alleles are present, they “codominate”, both traits are expressed

• blood type

Mendelian genetics ( complete dominance)

dominant allele masks the recessive trait completely

incomplete dominance,

• where the dominant trait does not completely mask the recessive trait

• result in the heterozygous genotype having a phenotype that is a “mix” between dominant and recessive

Sex-Linked Traits

• when traits are linked to either the X or Y chromosome

pedigree

•  family trees that show how traits are passed on in different generations

•  used to predict the chances of a trait being passed onto future generations