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115 Cards in this Set
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- Back
- 3rd side (hint)
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who discovered DNA is made of nucleotides? |
Levene (1905/30) |
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What did Griffiths (1928) discover? |
That bacteria can transfer genetic info, but didn't know how |
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Who discovered that that DNA contains equal amount of A&T, C&G? |
Chargaff (1949) |
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What did Hershey and Chase conclude? |
That DNA was made of genetic material, not proteins |
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What did Franklin determine? Was she credited? |
The helical structure of DNA using X-Rays No she was credited, Watson and Crick were |
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(1953) who deduced that DNA is a double helix structure? (Credited) |
Watson and Crick |
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What is building block of DNA |
Nucleotides |
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What is the backbone of DNA? |
The 5-Carbon Sugar/Phosphate |
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The rung of DNA? |
The 4 nitrogen bases |
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What are purines |
The bases that are doubled ringed- Adenine (A) and Guanine (G) |
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What are pyramidines |
The two bases that are single ringed- Thymine (T) and cytosine (C) |
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Structure of DNA? |
Double helix or twisted ladder |
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How are the bases held together in a nucleotides? |
By hydrogen bonds |
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In a nucleotides, what does each "rung" consist of? |
2 bases, (A-T) (T-A) (G-C) (C-G) |
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With hydrogen bonds, two _________ strands of nucleotides are held together |
Antiparallel |
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Chargaff Rule? |
Percent composition of (A) and (T) (C) and (G) Are always equal |
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4 types of nitrogen bases found in DNA |
Adenine (A), Guanine (G), Thymine (T), Cytosine (C) |
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4 types of nitrogen bases found in RNA |
Adenine (A), Guanine (G), Urasil (U), cytosine (C) |
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What is antiparallel |
Parallel but moving in opposite direction |
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Difference between DNA and RNA? (4) |
Sugar- DNA has deoxyribose and RNA has ribose Bases- DNA has (T) not (U) and RNA vise versa Strands: DNA has double, RNA has single Length: DNA is relatively longer than RNA |
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In nucleotides, how many HB b/w G and C |
3 |
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In nucleotides, how many HB b/w A and T |
2 |
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Why do hydrogen bonds in nucleotides break |
For DNA replication |
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Which phase of interphase does DNA replication occur |
During the (S) phase |
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Goal of DNA replication |
To make an exact copy of the entire strand |
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DNA is a _______ stand, and in replication, each stand is the ________ for the creation of a____________ stand |
Double, template, complementary |
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Original strands= |
Template strands |
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What does enzyme helicase do (3) |
They "unzip" the DNA by breaking the hydrogen bonds
"Free" nucleotide present in nucleus.
Also expose the unpaired nucleotides bases |
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What do the "free" nucleotides do? |
Pair up with exposed unpaired nucleotides on the template (original) strands |
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After replication, both strands are _______ |
Identical |
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Semi conservative replication |
Replication, when 2 new strands are formed, each with one original strand |
Semi=half there half not |
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In what order does genetic info pass? |
DNA -> RNA -> Proteins |
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Transcription |
When DNA is copied into RNA |
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Translation |
When the mRNA nucleotide sequence directs the synthesis of a polypeptide/protein with help of tRNA |
When the mRNA nucleotide directs the..... |
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Would all of the DNA be the "transcripted" gene |
No, only a portion |
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What would a protein look like after transcription |
A folded 3D structure |
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Proteins/polypeptides are made up of 20 ____________ |
Amino acids |
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What determines the characteristics of a protein? |
The sequence of amino acids |
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Does changing an amino acid change a protein? |
It may, or may not, depends on the amino acid |
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What are proteins used for |
Cell structure, enzymes, hormones, antibodies etc |
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What makes the genetic code |
The sequence of nucleotides |
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___________ directs the synthesis of a particular protein |
Each gene/segment of DNA |
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What is a gene |
A segment of DNA |
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3 DNA Molecules = # of amino acid/codon |
1 amino acid, 1 codon |
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What represents the 'start' and 'stop' signals |
Some of the triplet codes |
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Where does transcription take place |
In the nucleus |
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Transcription Definition |
Process by which the genetic code is transferred from DNA to RNA |
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Transcription part 1 process? |
Region of DNA 'unzips' and free mRNA nucleotide, match them with complementary base on the DNA. |
Start with unzipping |
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Transcription part 2 |
As the mRNA stand forms，it detached from the DNA, and mRNA Molecules leaves the nucleus |
As the MRNA strand forms |
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Transcription Definition |
Process by which proteins are synthesised using DNA instructions encoded in mRNA |
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Where does translation take place? |
In the cytoplasm |
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mRNA |
Messenger RNA |
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tRNA |
Transfer RNA |
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Order of anticodon is _____ To mRNA codon |
Complementary |
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Process of translation |
It uses tRNA (transfer RNA) to carry amino acids to the mRNA to the ribosome |
Using tRNA to.... |
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As the ________ moves along the mRNA, the tRNA molecules (with correct amino acid) are brought to the ribosome |
Ribosome |
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As amino acids are bonded together, the tRNA molecules |
Are released and may be reused |
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Difference between tRNA and mRNA |
tRNA= 4 separate molecules mRNA = one strand |
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What are mutations |
permanent changes to genetic material of an organism |
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Point mutuations |
change that affects one nucleotide; substitution |
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what are substitutions? |
replacing one base with another. |
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Do substitutions affect neighboring sequences? Provide example.
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no, they don't affect others. example, in a gene code, substitution of a 'c' only affects one carbon and not any others.
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Define semi conservative replication |
When each new DNA has a original strand and one new |
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What happens when the 'stop' codon on the mRNA is reached |
The amino acid chain is released, then folding like a proteins |
What is released, what happens after |
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Point at which the two template strands are separated are known as.... |
Replication bubble |
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What is okazaki fragment |
The lagging strands; short DNA segments |
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After replication finished the new DNA is only "half new". Why? |
Because DNA contains 1 original and 1 new strand |
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Genes definition |
Segment of DNA with specific instructions for making proteins |
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Some things proteins are responsible for |
Cell structure, enzymes, hormones, antibodies |
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What is RNA |
A nucleic acid with ribose as sugar |
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2 types of RNA |
mRNA, tRNA |
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What are the DNA polymerase and their function during the replication process |
Enzymes that add nucleotides to make DNA, acts as a proofread for the base pairs, and they sandwich themselves between parts of the DNA |
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First step of protein synthesis |
Transcription |
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Central dogma of molecular genetics |
DNA , RNA, Proteins |
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Transcription |
Info from segment of DNA being transferred to RNA |
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Function of mRNA in protein synthesis |
Takes info from DNA in nucleus to ribosome in cytoplasm |
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Codon |
3 nucleotides (mRNA) |
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How does only 4 nitrogen bases provide the code to build 20 different amino acid |
Different nucleotides sequences |
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Start (1) and stop code (3) |
Start (AUG) Stop (USA, UAG, UGA) |
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Role of mRNA in cell |
To message the RNA to copy DNA instructions |
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Anticodon |
Complementary base sequence on tRNA molecule |
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In DNA, what is the trait that reduce the amount of amino acids that are incorrectly translated? |
Redundancy |
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Role of mRNA in protein synthesis |
To transcribe a section of DNA; takes info to cytoplasm to ribosome where proteins are made |
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Do start codon have corresponding amino acid. How about end? |
Yes; No |
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Do stop codon need tRNA molecule |
No |
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Template stand vs coding strands in DNA |
Template- the stand that's copied (mRNA in transcription) Coding- complementary to template |
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What are mutations |
Permanent changes to the genetic material of an organism |
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How does ribosome know that protein synthesis is complete and process can turn off |
When stop codon is reached |
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What is frameshift mutations |
Changes that causes the entire strand after the point of mutation to be affected |
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Addition mutations |
Adding a base into the sequence |
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Deletion mutations |
A base is removed from the sequence |
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Silent mutations, what kind of protein will be made |
A mutation with no effect on a cell, the same protein would be made |
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Mis-sense mutations and kind of protein made |
A mutation that results in an altered protein, which can be harmful |
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Non-sense mutations |
Mutations that results in a gene being unable to code for a functional protein, results in no protein made |
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Example of frameshift mutations |
Addition/deletion of a base |
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mitochondria (and chloroplasts) contain their own DNA that is different from the DNA.... |
Inside the nucleus of the cells in where they are found |
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what part of cell does sperm give |
the nucleus in chromosomes |
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what part of cell does egg cell give |
the organelles, cytoplasm, and nucleus with chromosomes |
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when zygotes form, all of the cytoplasm + other organelles come from... |
egg cell |
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mitochondrial DNA (mtDNA) is identical to.... |
the mtDNA in an individual's mom |
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genetic recombination does.... |
create a DNA molecule with a new arrangement of genes |
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where does genetic recombination occur in nature? |
through crossing over (meiosis), purely by chance |
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where does genetic recombination occur artificially? |
in a lab; where specific gene combinations were created |
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what are the 2 tools used for genetic recombination? each used for? |
Ligase (joining DNA strands together to create new, artificially recombined DNA) Restriction Enzymes (to cut DNA at specific regions; like scissors) |
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what is gel electrophocesis/DNA fingerprinting? |
separation of DNA fragments according to mass and charge |
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what does gel elecrophocesis use? |
restriction enzymes, as DNA is cut into unequal fragment sizes |
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where are the fragments placed in DNA fingerprinting? What happens to the fragment? |
placed in a gel, and an electrical charge is applied |
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where does DNA fragments move to (ends of gel) and why |
DNA is (-) charged, so they move to (+) ends of gel |
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which moves faster; the smaller fragments or larger? why? |
the smaller, since they have less base pairs |
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examples of where DNA fingerprinting is used? |
in frequencies, crime scenes, and paternity testing |
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direct relationship b/w gene and enzyme? |
sequence of nucleotide in a gene determines the enzyme structure |
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events in protein synthesis? (part 1) |
1) mRNA forms on specific section of exposed DNA 2)MRNA exits the nucleus |
1) mRNA forms on specific section of exposed DNA
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events in protein synthesis (part 2) |
3) TRNA carries specific amino acid and binds to mRNA 4) amino acids are joined to form a polypeptide |
3) TRNA carries specific amino acid and binds to mRNA
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events in enzyme formation (part 1) |
1) mRNA leaves nucleus and attached to chromosomes in cytoplasm 2) tRNA transports amino acids to ribosomes |
1) mRNA leaves nucleus and attached to chromosomes in cytoplasm
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Events in enzyme formation (part 2) |
3) a polypeptide is released from the ribosomes 4) the polypeptide folds into enzyme shape |
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