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1-Abio Unit on Nucleic Acids

monomer of nucleic acids
Parts of a Nucleotide
5-carbon sugar, nitrogen base, and phosphate base
Sugar Molecule
5-Carbon Sugar deoxyribose
Nitrogen Bases
Purines and Pyrimidines
adenine and guanine
cytosine and thymine
phosphorus and 4 oxygen atoms
Base-Pairing Rules
Double Helix
twisted ladder shape-2 strands of DNA were wound around each other in a helical shape
Sugar Phosphate Backbone
makes of sides of Double helix (ladder)
Nucleotides (A, T, C, G)
Rungs of Double Helix (ladder) made by
Hydrogen Bonds
Rungs of Double Helix (ladder) held together by
DNA Replication
copying process by which a cell duplicates its DNA
Helicase (Role of Enzymes in DNA Replication)
catalyzes reaction that breaks H bonds joining nitrogen bases
DNA Polymerase (Role of Enzymes in DNA Replication)
joins individual nucleotides to produce a DNA molecule and "proofreads" the new DNA to insure that there are no mistakes (mutation)
Process of Replication (DNA)-Step 1
DNA helicase breaks bond between nitrogen bases and DNA unwinds
Process of Replication (DNA)-Step 2
DNA Polymerase reads template and pairs a complementary nucleotide to the exposed nitrogen base
Process of Replication (DNA)-Step 3
continues until 2 complete molecules have been produced
Process of Replication (DNA)-Step 4
Ligase fills in the gaps on the sugar phosphate backbone
strand of DNA used a a "model" for building the "new" strand
New strand that is produced using the template
The complementary bases are joined to the ________.
composition of Gene
Function of Gene
determines a trait: Contains genetic information that codes for a trait of characteristic
intervening sequence of DNA, does NOT code for protein
expressed portion of DNA codes for a protein
Multigene Families
encode proteins with similar sequences such as hemoglobin
Duplication of several ancestors
Transposition Gene
Transposons move around on the chromosome "jumping genes"
Importance of Transposition Gene
useful to researchers because they allow DNA to be altered
P53 Tumor
P53 genes stop tumor forming cells from divide. If a person only inherits one of these genes, they are at a higher risk for developing cancer.
P53 Tumor
mapped to chromosom 17
the master plans
a working copy
DNA Sugar
RNA Sugar
DNA Nitrogen Bases
A,T,C, and G
RNA Nitrogen Bases
5-A, Uracil, C, and G
# of DNA Strands
# of RNA Strands
DNA Complementary Bases
A=T, C=G
RNA Complementary Bases
A=U, C=G
DNA Location in Cell
RNA Location in Cell
Cytoplasm, Nucleus, Ribosome
DNA Function
stores genetic information
RNA Function
transmits genetic information
Messenger RNA
carries information from DNA into cytoplasm to ribosome for protein synthesis
Transfer RNA
transports each amino acid to the ribosome as it's coded in messages from mRNA
Ribosomal RNA
thought to help form peptide bonds between adjacent amino acids
Enzymes Used in Transcription
RNA polymerase binds to DNA and separates DNA
Process of Transcription- Step 1
A portion of DNA unzips (the portion that codes for a protein)
Process of Transcription- Step 2
RNA polymerase bonds to DNA and allows complementary RNA nucleotide to bond to DNA
Process of Transcription- Step 3
when complete, the mRNA strand separates from the DNA strand
DNA is transcribed more than __ because only the part that codes for that particular protein
Are both strands of DNA transcribed
result of transcription
decoding mRNA message into polypeptide chain
creates proteins
Codons (Translation)
3 consecutive nucleotides that code for 1 amino acid
found on mRNA
Anticodons (Translation)
3 consecutive nucleotides that code for 1 amino acid
Found on tRNA
Ribosome Structure
large and small subunit
Large Subunit
A and P site
A Site
holds a tRNA molecule that is carrying its specific amino acid attached to growing polypeptide chain
P Site
holds a tRNA molecule that is carrying its specific amino acid
Small Subunit
binds mRNA
Steps of Protein Synthesis
1. Initiation
2. Elongation
3. Termination
start codon positioned in P site, tRNA brings in second amino acid and a peptide bond forms
amino acids continue to be added to the growing polypeptide chain
stop codon which has no amino acid attached
the ribosome complex falls apart and the newly made protein is released into the cell
Lac Operon
to hydrolyze lactose into galactose and glucose
group of genes that code for proteins with related funtions
Beta Galactosidase
an example of gene regulation in prokaryotes
Regions of the Lac Operon
structural genes
RNA polymerase binding site that signals the beginning of the gene
between promoter and structural genes/controls RNA polymerase's access to structural genes acting like a switch turning on or off the transcription of the gene
Structural Genes
code for polypeptide, protein/enzyme
Role of Repressor
blocks transcription of lac genes
have DNA coding for every protein an organism needs to make
Specialized Cells
only need to make certain proteins
Coiled DNA
no transcription
Uncoiled DNA
transcription occurs
thought to position RNA polymerase (genes are often interrupted by these)
cause of mutation
change in DNA
Beneficial Mutations
can lead to adaptations which can allow organsims to live longer, reproduce more so more of the beneficial genes exist in the gene population
Point Mutations
mutation that occurs at a single nucleotide
Substitution (type of point mutation)
1 nucleotide is substitued for another
Frame Shift Poing Mutation
changes the DNA strand from that point on (addition/deletion)
when one nucleotide base is added
when one nucleotide is removed
T & C
simpler, pyrimidine (1 ring)
A & G
more complex-purines (2 rings)