Download BIO 101 – Exam #3 Study Guide 1 1) Nucleotides

BIO 101 – Exam #3 Study Guide
1) Nucleotides – sugar-based basic units of DNA; make up spine of DNA’s double helix
a. Sugar – deoxyribose
b. 1 of 4 Nitrogenous bases
i. Purines
1. Adenine
2. Guanine
ii. Pyrimidines
1. Thymine
2. Cytosine
c. Phosphate – PO4
2) Chromosome replication – done through DNA
a. Synthesis occurs in the 5’ to 3’ direction
b. Leading strand – straight forward / continuous strand
c. Lagging strand – made by DNA polymerase and has to pair up new DNA nucleotides in pieces,
called Okazaki fragments, with DNA ligase linking the pieces together
3) Transcription & Translation
a. Transcription – making mRNA off a DNA template
b. Translation – translating RNA into protein
i. Initiation – ribosome goes to hook up with mRNA
1. AUG = start codon (Met)
ii. Elongation – adding of amino acids
iii. Termination – stopping proteins
1. 1 of 3 stop codons
4) Hydrogen bonds - form between complementary base pairs and hold the double helix together
a. 2 hydrogen bonds in Adenine & Thymine
b. 3 hydrogen bonds in Guanine & Cytosine
5) Purines & Pyrimidines
a. Purines
i. Adenine
ii. Guanine
b. Pyrimidines
i. Thymine
ii. Cytosine
iii. Uracil
6) Amino acids
a. 20 of them
7) R Group – what makes each amino acid unique
8) Mutations & Mutagens
a. Mutations – change in genes
b. Mutagens – thing that causes mutations
i. UV light
ii. Sun light
iii. Radiation
iv. Chemicals
v. Radon gas
9) Sequence of nitrogenous bases make up a gene
10) Codons – 3-nucleotide sequence in mRNA that specifies a particular amino acid or polypeptide termination
signal
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BIO 101 – Exam #3 Study Guide
a. Sense codon – all proteins start with AUG
b. Stop codon – all proteins end with UAA, UAG, or UGA
11) mRNA / rRNA / tRNA
a. mRNA – transcribed from a DNA template in order to create proteins
b. rRNA – protein production in ribosome
c. tRNA – used to bridge mRNA with one of 20 amino acids in proteins
12) Anticodon – unit made of 3 nucleotides that corresponds to 3 bases of an mRNA’s codon
13) Peptide bonds & dehydration synthesis
a. peptide bonds – bond formed when 2 amino acids group together
i. polypeptide bond – when 3 or more amino acids group together
b. dehydration synthesis – making peptide bonds through loss of water
14) Complimentary base pairing – pairing DNA with sense codon (mRNA) for translation (tRNA)
15) Sense (template) strand & antisense strand of DNA
a. Sense strand – strand used to make RNA
b. Antisense strand – strand not used to make RNA
16) DNA – double strand (double helix), thymine, deoxyribose
17) RNA – single strand, uracil, ribose
18) Polypeptides & proteins assembled in cytoplasm
19) DNA is in nucleus
20) tRNA = ~80 nucleotides
21) tRNA/mRNA/rRNA = transcribed from nucleus
22) DNA structure resembles a twisted ladder
a. Rungs of ladder = nitrogenous bases
b. Backbone of ladder = linked sugar (deoxyribose) + phosphate group
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