ECHS DNA, RNA, & Protein Synthesis

how did the scientist frederick griffith contribute to the discovery of dna and its structure

he tried to figure out why bacteria made people sick; discovered the nature of the gene during experiments with mice; inferred genetic information being transferred from one mouse to another

what did the scientist rosalind franklin do to contribute to the discovery of dna and its structure

she was the first to photograph a picture of dna

what did the scientists watson and crick do to contribute to the discovery of dna and its structure

model of dna as a double helix; 2 strands wround each other

what does dna stand for

deoxyribonuclecic acid

dna is the genetic code for making what

proteins

what is the human genome project

scientists attempting to sequence all human dna

how many base pairs are found in the human genome

3 billion

what are the three rules of dna in heredity

storing, coping, and transmitting

where is dna located in the eukaryotic cells

nucleus

where is the dna located in the prokayotic cells

cytoplasm

what is the monomer of for nucleic acids

nucleotides

what is the first component of a dna nucleotide

five-carbon sugar (deoxyribose)

what is the second component of a dna nucleotide

a phosphate group

what is the third component of a dna nucleotide

nitrogenous base

how are the nucleotides held together

covalent bonds

What are the 4 bases found in DNA

adenine, guanine, cytosine, thymine

which of the bases are purines (two rings)

a and g

which two bases are pyrimidines (one ring)

c and t

according to DNA base pairing rule, what does a pair with

t

according to DNA base pairing rule, what does c pair with

g

what is Chargaff’s rule

the observation that a=t and g=c

what type of bonds for DNA’s double helix

hydrogen bonds

replication

identical copy of DNA made

original strand

old strand of dna

complementary strand

new strand of dna

dna polymerase

principal enzyme in dna replication - joins individual nucleotides to produce complementary strand of dna

what does the helicase enzyme do

enzyme that unwinds and opens the double helix

what does the primase enzyme do

enzyme that synthesizes short RNA sequences called primers. these primers serve as a starting point for DNA synthesize

what does the DNA ligase enzyme do

enzyme that aids in joining fragments during replication. responsible for sealing the dna backbone by crafting covalent bonds between the phosphate and one nucleotide to the sugar of another

what is the replication fork

where the dna unzips and breaks the hydrogen bonds holding the 2 dna strands together. site within the dna molecule where replication takes place.

what is the leading strand

continuously synthesized toward replication fork in the 5’ - 3’ direction

what is the lagging strand

since dna is always synthesized in the 5’ - 3’ direction, the lagging strand is put together in short pieces called Okazaki fragments

what is semiconservitive replication

each of the two strands serve as a template from which new strands are copied. The new strand will be complementary to the parental strand. each new double strand consist of 1 parental strand and 1 new daughter strand

what is the first step in dna replication

1. Dna unwinds at the origin of replication

what is the second step in dna replication

2. new bases are added to the complementary parental strands. one new strand is made continuously (leading) while the other is made in pieces (lagging)

what is the third step in dna replication

3. primers are removed, new dna nucleotides are put in place of primers and the backbone of dna is sealed by dna ligase

compare dna replication in the leading strand versus the lagging strand

since dna can only be synthesized in the 5’-3’ direction, the leading strand can be synthesized continuously. the lagging strand is synthesized in short fragments (okazaki fragments) and then joined together by dna ligase

explain the semiconservative nature of dna replication

each of the 2 strand serve as a template from which new strands are copied. each new double strand is made up of one parental (old) strand and one new (complementary) daughter strand

how are the liner ends maintained

the action of the telomerase enzyme (telomerase attaches to the end of the chromosome and complementary bases are added to the end of the dna strand in order to replicate the ends of the chromosomes

what is the central dogma of biology

dna —> rna —> protein

what is dna made up of

single chain nucleotides:

• 5 carbon sugar called ribose

• phosphate group

• nitrogenous base

what are 3 way in which rna differs from dna

1. uracil instead of thymine

2. generally single stranded

3. ribose as the sugar

what is mRNA

it carries instruction from the dna in the nucleus to the ribosomes in the cytoplasm (messenger rna)

what is rRNA

(ribosomal rna) combine with proteins to form ribosomes

what is tRNA

(transfer rna) carry amino acids to ribosomes

identify and describe the first of two part of protein synthesis

(DNA—>RNA) mRNA made from DNA occurs in the nucleus, so does replication

identify and describe the second of two part of protein synthesis

translation (RNS —> Protein) the cells use mRNA to make proteins, mRNA codon is read and tRNA brings in the correct amino acid to form a chain of amino acids (polypeptide) make protein. occurs in the ribosome.

translation occurs where

the nucleus

______ is made from _____

RNA ; DNA

what is the genetic code for mRNA/transcription

a pairs with u and c pairs with g

genes contain instructions for assembeling what

amino acids

what is a codon

3 consecutive nucleotide on mRNA that specify a particular amino acid

what is the the first step of transcription

initiation - begins when DNA is unwounded, forming a transcription bubble enzymes and to other proteins bind at the prompter

what is the second step of transcription

elongation - enzyme DNA polymers track along the DNA template, synthesizes mRNA in the 5’ and 3’ direction, and unwinds the rewinds as it is read

what is the third step in transcription

termination - the process of transcription is complete

explain how the prokaryotic gene structure may affect transcription results

allows for transcription of multiple genes at one time prompter, gene 1, gene 2, gene 3

explain how the eukaryotic gene structure may affect transcription results

requires further processing after transcription prompter, exon 1, intron 1, exon 2

what is the 5’ cap when explaining how the eukaryotic gene structure may affect transcription results

added RNA-stabilizing proteins prevent deration and aids in initiation

what is the introns vs exons when explaining how the eukaryotic gene structure may affect transcription results

segment of protein - coding sequencing - leaving behind exons - segments of protein - coding sequence - process of removing introns and rewinding exons is called splicing

what is the poly a tail when explaining how the eukaryotic gene structure may affect transcription results

stretch of RNA that has only adenine base that protects from degradation and aids in termination

where does translation occur

occurs on the ribosome

_______ is decoded to make _______

RNA; polypeptide chains

What is the first stage of translation

initiation - everything assembles

what is the second stage of translation

elongation - the code is read and converted

what is the third stage of translation

termination - stop signal is reached

when comparing the regulations of gene expressions in prokaryotes and eukaryotes explain the prokaryotic cells

simple transcription and translation can occur simultaneously; gene expression primarily regulated during transcription

when comparing the regulations of gene expressions in prokaryotes and eukaryotes explain the eukaryotic cells

more complex; transcription occurs in nucleus and prior to translation that occurs on ribosomes in cytoplasm - regulation can be on may be different levels

what are the 5 different ways eukaryotic gene expression is regulated

1. epigenetic

2. transcriptionional

3. post-transcriptional

4. translational

5. post-translational

what are mutations

changes in genetic material

what are the two types of mutations

gene and chromosomal

explain point mutations

changes in one or a few nucleotides that occur at a single point in the DNA sequence

give an example of point mutations

substitution

what are the frameshift mutations

shift the ‘reading frame’ of the genetic message, changing every amino acid that follows the point of mutation

give 2 examples of frameshift mutations

insertion and deletion

what is chromosomal mutation

changes in the number or structure of chromosomes: a change in location of genes on chromosomes, change in the number of copies of genes

what are the 4 types of chromosomal mutations

1. deletion

2. duplication

3. inversion

4. translocation

what are significances in harmful mutations

• most have little or no effect on genes

• disrupt normal activities

• genetic disorders

• diseases

• cancers

significance in helpful mutation

• genetic variability

• evolution

• polyploidy - larger, stronger plants

• insects develop pesticide resistance, microorganisms adaptions

• increase bone strength