Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
80 Cards in this Set
- Front
- Back
What is the purpose of DNA replication? |
Before a cell divides into 2 new daughter cells, it needs to double the number of chromosomes. |
|
How do you remember the three steps of DNA Replication? |
UUNNBCPANB (unidentified unsub never needs binoculars cuz prentice always needs bullets) Unwind, Unzip, New, Nucleotides, Bind, Comp., Pairs, Adjacent, Nucleotides, Bind |
|
Where is the location of DNA Replication? |
Nucleus, mitochondrion, and plant chloroplasts |
|
What two enzymes are required for DNA Replication? |
Helicase and DNA Polymerase |
|
What are the products of DNA Replication? |
-2 DNA molecules that contains 1 original/parental strand + 1 new complementary strand -semi-conservative replication (.5 of original DNA is conserved and matched with a new comp. strand) |
|
1. Unzipping |
-2 strands of DNA unwind and unzip the H-bonds between N-bases pairs using Helicase -each strand now acts as a template |
|
2. Complementary Base Pairing |
-new nucleotides present in the nucleus (TCAG) bond with the complementary pairs on the parental using DNA polymerase |
|
3. Joining of Adjacent Nucleotides |
-Adjacent nucleotides join/form a bond (phosphodiester bond) with the help of DNA polymerase ("proof reader") to form new sugar-phosphate backbone resulting in 2 identical DNA molecules -this is referred to as semi-conserative |
|
What is Recombinant DNA? |
DNA/genome from two different organisms are spliced together to obtain a desired trait or perform a specific function The manipulation of a genome from 2 or more sources (such as bacteria, plants, animals) |
|
What is a genome? |
Heredity information |
|
What are two examples of recombinant DNA having to do with transgenic (genetically altered/GMO's) organisms? |
Transgenic animals used to increase productivity, produce pharmaceuticals, produce organs, research in cancer/tumor cells, etc. Transgenic bacteria used for vaccines, biofilter airborne pollutants, synthesize hormones, enzymes for making cheese, clean oil spills, etc. |
|
What are some other examples of recombinant DNA? |
To give an organism a metabolic capability it didn't possess before (goats and spiders- super high protein milk) Production of DNA probes for paternity/maternity, body ID, evolutionary relationships |
|
What is protein synthesis? |
The synthesis of proteins from amino acids. |
|
Where does protein synthesis occur? (generally, not specifically. Where in cell?) |
Nucleus and cytoplasm |
|
What does protein synthesis require? |
A source of ATP |
|
How are genetic codes for proteins arranged? |
In triplet codes/sequences (TAC, CAT, ACG, GAG) |
|
What is the exact site of protein synthesis? |
On the ribosomes in the cytoplasm. |
|
What is the role of DNA in protein synthesis? |
-provides a template for mRNA to be produced -contains genetic information/genetic code/triplet codes/genes for the synthesis of protiens |
|
What is the role of mRNA in protein synthesis? |
-carries the transcribed triplet codes/coded message from the nucleus to the cytoplasm Eg. codons -sets the order of amino acids for protein synthesis by the sequence of codons -acts as a template to make proteins at the ribosomes during translation |
|
What is the role of ribosomes in protein synthesis? |
-provides a site for mRNA and tRNA to join together by complementary base pairing -site for protein synthesis where it translates mRNA and allows amino acids to bond (peptide)
|
|
What is a codon? |
3 bases/nucleotides in a RNA sequence which specify a single amino acid AAA, UCA, GUG |
|
What makes up a ribosome? |
-rRNA and protein make up the small subunit and the large subunit of a ribosome -small subunit --> binding site for mRNA -large subunit --> 2 binding sites for the tRNA -----------------------> amino acid and a d.s. site |
|
What is the role of tRNA in protein synthesis? |
-carries the specific amino acid to the ribosomes where its anticodon (triplet of A U C or G) complementary base pairs with a specific mRNA codon |
|
What is the importance of methionine? |
AUG is the start codon on mRNA because it triggers the start of translation. |
|
What is the importance of UAA, UGA, UAG? |
They are the stop codons on mRNA. They signal the ribosomes to stop linking amino acids together, terminate protein synthesis and release the protein. |
|
What are the two steps (acts) of protein synthesis? |
Transition and Translation |
|
What are the three smaller parts (scenes) of the two 'acts'? |
Initiation Elongation Termination |
|
Transcription; Initiation |
-RNA polymerase initiates transcription by locating and binding to the beginning of a gene/code on the DNA |
|
Transcription; Elongation |
-Helicase unwinds and unzips DNA, breaks H-bonds and provides a template for mRNA formation -RNA polymerase travels down the template and complementary base pairs RNA polymerase with DNA codon forming a mRNA -RNA polymerase joins adjacent nucleotides to mRNA forming the sugar phosphate backbone |
|
Transcription; Termination |
-RNA polymerase reaches termination sequence at end of gene code/gene and STOPS mRNA synthesis -RNA polymerase releases the mRNA and detaches from the DNA -mRNA exits nucleus through it's pores & enters the cytoplasm -DNA rejoins |
|
Where does Transcription occur? |
Nucleus |
|
What is the product of Transcription? |
mRNA |
|
What are the required enzymes for Transcription? |
Helicase and RNA Polymerase |
|
Where is the location of Translation? |
Cytoplasm at the ribosome |
|
What is the product of Translation? |
Protein/polypeptide chain |
|
What happens before Initiation in Translation? |
tRNAs in the cytoplasm attach the correct amino acid to the one end (aided by enzymes) |
|
Translation; Initiation |
-tRNA~methionine/start codon binds to small subunit and this binds to the mRNA -tRNA anticodon (UAC) complementary pairs with mRNA start codon (AUG - methionine) -large subunit binds to the small subunit making the ribosome |
|
Translation; Elongation |
-another tRNA~aa with it's anticodon complementary base pairs with mRNA codon on ribisome -ribosomes move along one codon to receive the next incoming tRNA~aa -amino acids (aa) undergoes dehydration synthesis and forms a peptide bond -empty tRNA will bond with another aa in the cytoplasm |
|
Translation; Termination |
-synthesis of polypeptide until a stop codon on mRNA -there are no tRNA molecules with anticodon for the stop codons (protein release factors recognises these codon when they arrive at the mRNA) -termination of protein synthesis occurs -the polypeptide chain and mRNA release from the ribosomes and the ribosome subunits seperate |
|
Agents that cause mutations are ____________. |
Mutagens |
|
Mutagens include... |
UV Radiation X-Rays Gamma rays Industrial chemicals Formaldehyde Chemicals in cigarette smoke |
|
What also causes mutations, and how? |
Viruses They add or delete a nucleotide or by adding a new section of DNA from another organism (Viruses change a proto-oncogene (normal gene) into an oncogene/cancer-causing gene eg. HIV) |
|
All gene mutations involve altering ________________. |
The code/codons ie. Sequence of amino acids or number or sequence of N-bases within the DNA molecule during replication |
|
Altering the code for protein synthesis of proteins may result in _______________ _________ combining ________________ __________ _________ with _______________ _________ _________ and therefore function is impaired. |
Different codons Different amino acids Different protein shapes |
|
Diseases/disorders caused by gene mutations include... |
Sickle-cell anemia causing sickle shaped rbc's Cystic Fibrosis Muscular dystrophy |
|
If the protein is an enzyme, (enzyme + substrate) __________ may not occur or if the protein is a membrane protein, the ______ _______________ will not function properly. |
Reactions Cell membrane |
|
What are the three types of gene/DNA mutations? |
1. Deletion 2. Addition 3. Subsitution |
|
Deletion |
One or more nucleotides are deleted (frameshift mutation |
|
Example of Deletion |
Normal DNA TAC|GGG|ATG|TCA Mutation TAG|GGA|TGT|CA (the c of the first codon was removed) |
|
Addition |
One or more nucleotides are added (frameshift mutation) |
|
Example of Addition |
Normal DNA TAC|GGG|ATG|TCA Mutation ATA|CGG|GAT|GTG|A (a was added) |
|
Substitution |
Involves a replacement of a single nucleotide with another, and therefore a change in a specific codon (point mutation) |
|
Examples of Substitiution |
Normal DNA TTC mRNA AAG = Lysine
Mutated DNA ATT (A substituting for T) mRNA UAG = STOP
Drastic Effect as UAG is a stop codon. the resulting protein may be too short and unable to function for the cell. |
|
What is an example of single base substitution mutation causing a disease/disorder? |
Sickle-cell anemia Glutamate (DNA code CTC or CTT) is changed into Valise (DNA code CAT, CAG, CAA, CAC)
|
|
Sickle-cell anemia |
Normal DNA ...GGA|CTC mRNA ...CCU|GAG Amino Acid -Proline-Glutamate
A substitutes for T mutation (single base substitution) Normal DNA ...GGA|CTC Mutated DNA ...GGA|CAC
mRNA ...CCU|GUG Amino Acid -Proline-Valine |
|
Drastic effect as sickle-cell anemia alters ONE codon and changes _____________ to _____________. Their chemical properties (are the same/differ) which causes RBC's to become _______________ __________-__________. These rigid inflexible cells cannot move through blood vessels easily which _________ blood vessels, and therefore (less/more) transport of gases to tissue cells occurs. |
Gultamate Valine Differ Abnormally Sickle-shaped Blocks Less
|
|
The term codon is used to describe a sequence of bases in
-DNA -rRNA -tRNA -mRNA |
mRNA
|
|
Which of the following is the second step of DNA replication?
A. The formation of 2 new DNA molecules B. Complementary base pairing of nitrogenous bases C. The breaking of hydrogen between the nbases D. The joining of bonds between the sugar and phosphate backbone |
B
|
|
The process of translation occurs at the ribosome. True or false?
|
True
|
|
The genetic code is based upon the reading of how many bases at a time?
1 2 3 4 |
3
|
|
How many codons are needed to specify 3 amino acids?
|
3
|
|
What processes happen in the nucleus?
|
Transcription and replication of DNA
|
|
What defines a codon?
|
The genetic code word of three bases on mRNA that specify one amino acid
|
|
The term codon is used to describe a sequence of bases in
-DNA -rRNA -tRNA -mRNA |
mRNA
|
|
Which of the following is the second step of DNA replication?
A. The formation of 2 new DNA molecules B. Complementary base pairing of nitrogenous bases C. The breaking of hydrogen between the nbases D. The joining of bonds between the sugar and phosphate backbone |
B
|
|
The process of translation occurs at the ribosome. True or false?
|
True
|
|
The genetic code is based upon the reading of how many bases at a time?
1 2 3 4 |
3
|
|
How many codons are needed to specify 3 amino acids?
|
3
|
|
What processes happen in the nucleus?
|
Transcription and replication of DNA
|
|
What defines a codon?
|
The genetic code word of three bases on mRNA that specify one amino acid
|
|
The term codon is used to describe a sequence of bases in
-DNA -rRNA -tRNA -mRNA |
mRNA
|
|
Which of the following is the second step of DNA replication?
A. The formation of 2 new DNA molecules B. Complementary base pairing of nitrogenous bases C. The breaking of hydrogen between the nbases D. The joining of bonds between the sugar and phosphate backbone |
B
|
|
The process of translation occurs at the ribosome. True or false?
|
True
|
|
The genetic code is based upon the reading of how many bases at a time?
1 2 3 4 |
3
|
|
How many codons are needed to specify 3 amino acids?
|
3
|
|
What processes happen in the nucleus?
|
Transcription and replication of DNA
|
|
What defines a codon?
|
The genetic code word of three bases on mRNA that specify one amino acid
|
|
What are the nucleotide pairings of DNA with mRNA?
|
TA. AU. CG. GC
|
|
What are the nucleotide pairings of tRNA with mRNA?
|
AU. CG. GC. UA.
|
|
What is changed in sickle cell
anemia? |
Glutamate is changed to Valine
|