Chapter 10 Review

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1 Οκτ 2013 (πριν από 3 χρόνια και 10 μήνες)

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Honors Biology
Chapter 10
Cram Sheet

DNA



Structure and Function



Watson and Crock were the scientists credited with discovering the structure of the DNA molecule.



DNA is located in the nucleus of the cell.



DNA is named for the sugar, deoxyribose.



DNA is
double helix made up of nucleotide sequences




Sugar
-
phosphate backbone and nitrogen bases form rungs



Sugar


deoxyribose



Bases


A, G, C, T



Complementary base pairing
-

A
-
T; G
-
C




Hydrogen bonds bind bases together



Nucleotide is basic unit of nucleic ac
id





Two groups of molecules




Replication


process
by which DNA makes an identical copy of itself; occurs just before cell division





Errors in replication can cause mutations which can lead to cancer. Causes of cancer include UV
radiation, and genetic

mutations

Protein Synthesis



Flow of genetic information is from DNA


RNA


Protein






Protein synthesis also called gene expression



Two steps to protein synthesis

o

Transcription


process by which DNA makes RNA


o

Translation


process by which RNA
assembles proteins




3 types of RNA

o

mRNA


carries genetic code out of nucleus to ribosome

o

tRNA


bring amino acid to the ribosome

o

rRNA


forms part of ribosomal unit where mRNA and tRNA “hook up” to assemble
polypeptide chain.




Amino acids are the buildi
ng blocks (monomers) of proteins. Proteins are polypeptide chains joined
by peptide bonds



The genetic code is the term for the rules that relate how a sequence of nitrogen bases in
nucleotides corresponds to a particular amino acid.



In the genetic code, th
ree adjacent nucleotides (“letters”) in mRNA specify an amino acid (“word”) in
tRNA.



The triplet of letters in mRNA is called a codon and is complementary to the triplet of letters in tRNA
called the anticodon.




There are 20 amino acids in nature but
many codons so more than one codon can specify the same
amino acid. Ex) GUU, GUC, GUA, GUG specify for the amino acid Valine.



The start codon AUU specifies for the amino acid Methionine. The stop codons are UGA, UAA, and
UAG but do not specify any amino a
cid.



The human genome is the complete genetic content of a human. There are 30,000 genes. The new
field is called bioinformatics and studies the information in the genome. This information is
important as scientists try to figure out what causes genetic di
sorders and looks for treatments for
them.



Compare and contrast the differences between DNA and RNA




Make sure you can take a specific code and go backwards and forwards and look up the genetic
code on the chart. The chart may look like this on the EOC so I will have this
chart below
on the test.



Which amino acid chain would be produced by the DNA sequen
ce below?







If a portion of a DNA strand has the base sequence TACGCA, what will be the base sequence of
the mRNA strand transcribed?




Make sure that you can
identify and
label the structures in a nucleotide and in the process of
transcription from a d
iagram like below: