topic 6 - dna, rna, and protein synthesis
steps of dna replication:
1. helicase separates the dna strands 2. dna polymerases add each complementary nucleotides to each of the original strands 3. dna polymerases are released. two new molecules identical to the original dna molecule result
if an organism's genome is made up of 20% adenine, what percentage must the thymine equal?
20%
What is the mrna sequence for the following dna sequence? TAC TAT GGC ATG
AUG AUA CCG UAC
elements that make up protein are...
CHONS - carbon, hydrogen, oxygen, nitrogen, sulfur
elements that make up dna are...
CHOPN - carbon, hydrogen, oxygen, phosphorus, nitrogen
If one dna molecule runs CCCAAAGGGTTT then what would its complementary dna strand be?
GGGTTTCCCAAA
what is the amino acid sequence for the following mrna sequence? use the universal genetic code wheel to determine the amino acid identity and use the three letter abbreviation for the amino acid. AUG GAA AAG UCU UAA
MET-GLU-LYS-SER-STOP
dna is...
a double-stranded helix spiral held together by hydrogen bonds between the bases
chemical analysis of a protein shows there are only 575 amino acids in a protein that normally has 1,273 amino acids. what most likely happened?
a mutation that substituted an amino acid for a stop codon.
a nucleotide is made up of...
a sugar, a phosphate, and one of the four nitrogenous base
bacteriophage
a virus that infects only bacteria
dna polymerase's role in dna replication is to...
add new nucleotides to form a complementary strand of dna
erwin chargaff's base pairing rules state that the following base pairs in dna...
adenine pairs with thymine ; guanine pairs with cytosine
a mutation made during dna replication can... - have no effect on the resulting amino acid sequence - lead to new traits - cause an amino acid to be substituted by a stop codon
all of the above
polymers are large macromolecules, like proteins, that are made up of smaller parts called monomers. what are the monomers of proteins?
amino acids
the two strands of a dna molecule run in opposite directions with one running in the 5' to 3' direction and the other in the 3' to 5' direction. what is the name of this type direction?
anti-parallel
a 3 base sequence of mrna that codes for an amino acid is a...?
codon
nitrogenous bases...
contain nitrogen and is a base. its purines are A and G and its pyrimidines are T and C
what is the backbone of dna?
deoxyribose sugar and phosphate
what conclusions did Griffith, Avery, and Hershey & Chase come to following their experiments?
dna molecules are the hereditary factors that transformed bacteria
which enzyme also has "proofreading" capabilities and can correct errors made during dna replication to decrease mutations?
dna polymerase
rosalind franklin's lab took the famous photo 51, an image made using x-ray crystallography. this led the discovery of...
dna's double helix structure
a segment of dna located on a chromosomes that codes for a protein
gene
review the original and mutated dna strand below. What type of mutation is this? original: TAC TCC GCG ATC mutated: TAC TGC CGC GAT
insertion frameshift mutation
a substitution mutation resulted in a change in the codons below. the "G" in UAG is a mutation. what type of point mutation is this? original mrna strand: AUG UAC CCC UAA mutated mrna strand: AUG UAG CCC UAA
nonsense point mutation
polymers are large macromolecules, like DNA, that are made up of smaller parts called monomers. what are the monomers of DNA?
nucleotides
translation (rna is translated to protein)
occurs in the cytoplasm
transcription (dna is transcribed to rna)
occurs in the nucleus
after semi-conservative replication, the two newly created dna molecules will each have..
one original strand and one new strand
review the statements below then choose which are correct: - the strands of dna run antiparallel - the central dogma of molecular biology is protein → rna → dna - dna replication is said to be semi-conservative
only 1 and 3 are right
genes contain instructions for assembling
proteins from dna
a substitution mutation resulted in a change in the codons below. the "C" in CUA is a mutation. what type of point mutation is this? original mrna strand: AUG UUA GGG UAA mutated mrna strand: AUG CUA GGG UAA
silent point mutation
what type of mutation does not result in different proteins and new traits?
silent point mutation
what is a function of helicase?
the enzyme breaks hydrogen bonds in dna, exposing dna nucleotides on the inside of the helix
what is a function of dna polymerase?
the enzyme proofreads the dna and ensures mutations are fixed
replication fork
the y-shaped region that results when the two strands separate
the process of making mrna from a dna template is called?
transcription
hydrogen bonds
weak, but there are millions and millions of them in a single molecule of dna.