Bio Unit 7

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Terms in this set (...)

Gene
Segments of DNA that are the units of heredity
DNA
Controls the development of time and all cellular activities
Which two scientists discovered the structure of DNA
Watson & Crick
Nucleotide
base unit that makes up DNA
What are the 3 parts of a Nucleotide
Sugar, Phosphate, Base
What are the 2 Purines (large)
adenine & guanine
What are the 2 Pyrimadines (small)
thymine & cytosine
What are the four bases that make up the genetic code of life
adenine, guanine, cytosine, thymine
What does adenine bond to
thymine
what does guanine bond to
cytosine
DNA molecule is made of how many nucleotides
2 strands
What bond holds nucleotides together
hydrogen
write the complementary strand: ATGCCTAAGTGC
TACGGATTCACG
What do the letters DNA stand for
Deoxyribonucleic acid
In what organelle is DNA located in
nucleus
In what structure in the nucleus is the DNA found?
eukaryotic cell
What structure is DNA?
Double helix
What type of sugar is found in DNA
deoxyribose
DNA replication
process bu which DNA copies itself
When does DNA replications occur
During interphase of the cell cycle (S phase)
What are free-floating nucleotides used for
making new DNA
What are the steps of Replication
1. DNA helix untwists & unzips, 2. each side of the DNA serves as a template, 3. Hydrogen bonds form between the new nucleotides and the DNA chain, 4. The 2 new molecules of DNA rezip & retwist
What is the end result of DNA replication
forms 2 identical copies of original DNA (for each daughter cell)
Triplets
3 base sections on a DNA molecule
What is the importance of DNA
DNA controls which proteins are made. Proteins then become enzymes that determine traits and control cell processes. Thus, DNA controls the proteins that are made.
Protein
chain of amino acids
Enzymes
proteins that control all the chemical reactions of life
What is the role of DNA
To build proteins which carry cellular messages and Hereditary info
RNA (ribonucleic acid)
working instructions of genes
mRNA
carries instructions from DNA to proteins on the ribosomes
tRNA
carries amino acids to ribosomes
rRNA (ribosomal)
helps maintain ribosomes
transcription
making mRNA from DNA (nucleus)
What are the steps of Transcription
1. DNA untwists & unzips, 2. One strand serves as a template, 3. RNA polymerase lines up RNA nucleotides, 4. Continues until a "stop" signal is reached, 5. mRNA leaves the nucleus and binds to a ribosome (cytoplasm)
codon
3 base pairs on mRNA
Translation
tRNA "reads" the mRNA to assemble a protein (cytoplasm)
What are the steps of translation
1. tRNA carries amino acids to the ribosome, 2. tRNA lines up the amino acid by reading the codons on the mRNA, 3. peptide bonds form between the amino acids, 4. the protein molecules breaks free and tRNA is reused
Anticodon
3 bases on tRNA
genetic code
amino acids and stop signals that are coded for each of mRNA codons
How many codons are there in the genetic code
64
how many amino acids are there in the genetic code
20
What is the importance of proteins
carry out cellular messages
Explain difference between DNA and RNA
DNA has 2 strands and RNA only has 1
RNA has what nitrogen base in place of thymine
Uracil
What happens to mRNA once its made?
binds to ribosome
what substance is produced in transcription
mRNA
What kind of bonds form between amino acids
peptide bonds
what is the start codon of all proteins
AUG
what are the 3 "stop" codons
UAA, UAG, UGA