gene action: from dna to protein Flashcards
they are the blueprints of life
dna sequences
- instructions are coded in the sequence of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
what are the effects of dna and gene expression in simple terms
dna:
did not change
gene expression:
some become active, others become less active
due to its unique enviro in space
what changed when the astronaut came back to earth as he stopped eating the packaged space food
his intestinal microbiome
- which is the collection of bacteria and other organisms in his gut
what happened to the chromosomes’ telomeres in space and in earth
telomerase protect ends of chromosomes
in space: lengthened
in earth: return to normal
it comprise one of the 3 major types of nutrients and are abundant in where
proteins
(meats, eggs and legumes)
what happens when we consume proteins
digestive enzymes breakdown into amino acids - which are small enough to enter the bloodstream (through the interior lining of the small intestines)
how many amino acids exist in the human body
500
how does the amino acids from the bloodstream used to make new proteins
process is guided by RNA molecules transcribes from genes (DNA) guide their assembly into new protein molecules
[Imagine amino acids as building blocks. They get transported into cells, where RNA (which is like a set of instructions copied from DNA) acts as a blueprint. This blueprint tells the cell exactly how to connect these amino acid building blocks in the right order to create new proteins.]
how many amino acids does the body build its proteins
20 only
9 essential - body cannot synthesize them, must’ve come from diet
6 conditionally essential - body can manufacture them except for certain circumstances (born prematurely & metabolic disease)
5 non essential - body can make them, so do not need to get them from diet
what is the framework of the amino acid
central carbon that bonds
- amino grp NH2
- acid grp COOH
- hydrogen
- R group: distinguishes the amino acids
how does the amino group of one amino acid attaches to the acid grp of another
peptide bond
a protein consists of one or more long chains of amino acids
polypeptides
shorter chains of amino acids
peptides
a protein’s three dimensional shape
conformation
what happens if there are no proteins in the body
blood couldnt clot
muscles couldnt contract
antibodies couldnt fight infection
we wld have no hair, skin or connective tissues
can no longer walk because the motor neurons cannot manufacture gigaxonin protein
giant axonal neurotherapy
why do people who have cystic fibrosis have respiratory and digestive problems
as ion channel proteins cannot fold properly
- if the body cant make certain proteins = serious health problems
How do proteins link the information in our genes (genotype) to the traits we see and experience (phenotype)
produced based on instructions from our genes, and these proteins carry out functions that result in the traits we see (phenotype).
this process starts by copying a gene’s instructions into a usable form (RNA), which then guides the assembly of proteins in the body.
what are the 2 important steps that cells go through to make proteins
transcription:
makes a copy of a gene’s instructions from DNA in the form of RNA
RNA is like a messenger that carries the genetic information out of the cell’s nucleus and into the cytoplasm
translation:
once the RNA is in the cytoplasm, the cell reads the instructions in the RNA to put together the right amino acids to build a protein
after the amino acids are linked, the protein folds into a three-dimensional shape, which is necessary for it to do its job in the body
why do the process of transcription and translation happen continuously
as proteins are constantly being made to keep the body functioning and to give each cell its specific role
it is the relationship between nucleic acids and proteins as a directional foe of information
central dogma
* Watson and Crick published their structure of DNA in 1953
DNA vs RNA
index card
the bases of an RNA sequence are complementary to those of one strand of the double helix
template strand
- the non template strand of the DNA double helix - coding strand
this is an enzyme that builds RNA molecules
RNA polymerase
what are the similarities between RNA and DNA
nucleic acids
consisting of sequences of nitrogen-containing base joined by sugar phosphate backbones `
types of RNA (size)
function
mRNA, messenger (500 to 4,500)
encodes aa sequence
rRNA, ribosomal (100 - 3,000)
associates w proteins to form ribosomes, which structurally support and catalyze protein synthesis
tRNA, transfer (75 - 80)
transport specific aa to the ribosomes for protein synthesis
