Chp 12 and 13 Bio
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Terms in this set (65)
By observing bacterial transformation, Avery and other scientists discovered that the nucleic acid DNA stores and transmits genetic info from one generation of bacteria to the next.
What clues did bacterial transformation yield about the gene?
scientist who experimented with bacteria to find out how it made people sick. Discovered process of transformation.
the transfer of genetic material in the form of DNA fragments from one cell to another or from one organism to another
a Canadian biologist that performed an experiment with enzymes; he discovered that DNA is the nucleic acid that stores and transmits the genetic information from one generation of an organism to another
Hershey and Chase's experiment with bacteriophage confirmed Avery's results, convincing many scientists that DNA was a genetic material found in genes -- not just in viruses and bacteria, but in all living cells
What role did bacterial viruses play in identifying genetic material?
a virus that infects bacteria; used in some forms of recombinant DNA to transport foreign DNA into a host cell
The scientist who worked with Martha Chase to prove that genetic material is composed of DNA
showed that DNA was the genetic material of the phage T2
In 1952, Alfred Hershey and Martha Chase performed experiments showing that DNA is the genetic material of a phage known as ___
The DNA that makes up genes must be capable of storing, copying and transmitting the genetic information in a cell
What is the role of DNA in heredity?
DNA is a nucleic acid made up of nucleotides joined into long strands or chains by covalent bonds.
What are the chemical components of DNA?
five-carbon sugar that is a component of DNA nucleotides
a functional group consisting of a phosphorus atom covalently bonded to four oxygen atoms
The base that pairs with Thymine in DNA
a purine base found in DNA and RNA
The base that pairs with Guanine with DNA
The base that pairs Adenine in DNA
Basic units of DNA molecule, composed of a sugar, a phosphate, and one of 4 DNA bases
The clues in Franklin's X-ray pattern enabled Watson and Crick to build a model that explained the specific structure and properties of DNA.
What clues helped scientists solve the structure of DNA?
Woman who generated x-ray images of DNA, she povided Watson and Crick with key data about DNA
discovered the secret of DNA structure in the 1950s with Francis Crick by using Rosalind Franklin's pictures of DNA
English biochemist who (with Watson in 1953) helped discover the helical structure of DNA (born in 1916)
The double-helix model explains Chargaff's rule of base pairing and how the two strands of DNA are held together.
What does the double-helix model tell us about DNA?
Who discovered that the amount of adenine equals the amount of thymine, and amount of guanine equals cytosine?
principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine
the opposite arrangement of the sugar-phosphate backbones in a DNA double helix
the intermolecular force in which a hydrogen atom that is bonded to a highly electronegative atom is attracted to an unshared pair of electrons of an electronegative atom in a nearby molecule
How many hydrogen bonds are between G and C?
How many hydrogen bonds are between A and T?
Because they must make a 3 ring rung, and C and G can both make 3 hydrogen bonds, and A and T can both make 2 hydrogen bonds
Why do G bond with C, and A bond with T?
what role does dna polymerase play in copying dna?
dna polymerase is an enzyme that joins individual nucleotides to produce a new strand of DNA
the process which replicates dna
The role of enzymes
they unzip a molecule of DNA by breaking the hydrogen bonds between base pairs and unwinding the two strands of the molecule.Each strand the serves as a template for the attachment of complementary bases.
DNA tips at the end of chromosomes
restore length of telemeres that are shortened during DNA replication
prokaryotic DNA replication
chromosome is circular molecule of DNA; replication begins at a single origin of replication and proceeds in both directions towards termination
Eukaryotic DNA replication
replication may begin at dozens to hundreds of places on the DNA molecule, proceeding in both directions until the DNA is completely copied.
How does RNA differ from DNA
1. The sugar of RNA is ribose instead of deoxyribdose
2. RNA is single stranded while DNA is double stranded
3. RNA contains uracil in place of thymine
Functions of RNA
RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell
The most abundant type of RNA, which together with proteins, forms the structure of ribosomes, small organelles composed of two subunits. these molecules are made up of as many as 80 proteins
type of RNA molecule that transfers amino acids to ribosomes during protein synthesis
segments of DNA serve as templatesto produce complementary RNA molecules.
enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription
Region of DNA that indicates to an enzyme where to bind to make RNA
Long segments of nucleotides that have no coding information
A coding region of a eukaryotic gene. Exons, which are expressed, are separated from each other by introns.
long chains formed by joining amino acids together
sequence of nucleotides that specifies the amino acid sequence of a protein. Read three letters at a time and each "word" is three bases long and corresponds to a single amino acid.
Each three letter "word" in mRNA.
How do ribosomes assemble amino acids into polypeptide chains?
They use the sequence of codons in mRNA.
the decoding of an mRNA message into a protein.
the three unpaired bases in each tRNA molecule.
What is the central dogma of molecular biology?
Information is transferred from DNA to RNA to protein
the way in which DNA, RNA, and proteins are involved in putting genetic information into action in living cells.
heritable changes in genetic information
Gene mutations that involve changes in one or a few nucleotides. Include substitutions, insertions, and deletions
One base is changed to a different base. Usually affect no more than a single amino acid, sometimes they have no effect at all.
Insertions and Deletions
Point mutations in which one base is inserted or removed from the DNA sequence. The effects can be dramatic. Known as frameshift mutations because they shift the groups in every codon that follows the mutation.
mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide. Can change every amino acid that follows the point of the mutation. Can alter a protein so much that it is unable to perform its normal functions
chemical or physical agents in the environment.
What are the effects of mutations on genes?
They vary widely, some have little or no effect; and some produce beneficial variations. Some negatively disrupt gene function.
What are some harmful mutations?
Those that dramatically change protein structure or gene activity are the most harmful. Some harmful mutations are some cancers and sickle cell disease.
What are some beneficial mutations?
Mutations often produce proteins with new or altered functions that can be useful to organisms in different or changing environments. An example is the mutated mosquito genome causing many African mosquitoes resistant to the chemical pesticides once used to control them.
The condition in which an organism has extra sets of chromosomes.