Exam 1 Flashcards
What is the order of the processes that support the Central Dogma?
DNA replication, transcription, translation
Sometimes the sequence of DNA gets mutated and an adenine is paired to a cytosine. Why is this interaction unstable?
Because the chemical groups that form hydrogen bonds are in the wrong positions
True or False: In a long double stranded DNA molecule containing the genetic information for many genes, the template strand for one gene may be the non-template strand for another gene located in a different region of DNA.
True
What is the sequence of the RNA molecule encoded by the sequence of DNA 5’-ACTAGC-3’
5’-GCUAGU-3’
In a particular sample of DNA, if the amount of T is 70% of the total amount of pyrimidines, what percentage of the whole sample of DNA is made with G?
15%
Experiments by Avery supported DNA as the genetic material by showing that
only samples with DNA provided transforming activity
Which molecules were identified at the end of Miller and Urey’s experiment?
Amino Acids
What is a gene?
A section of DNA that codes for RNA
A water molecule contains what type of bond?
Polar covalent
DNA is required for _____ and _______ of genetic informaiton
Storage and transmitting
Who found out about x-ray crystallography can show the 3D structure of a substance. And what did he/she see?
Rosalind Franklin, she saw DNA double helix. Watson and Crick took credit for her work
What is carbs, monomer, polymer, bond, element, and give an example
monosaccharide, polysaccharide, glycosidic linkage, (C,H,O), Ribose/Deoxyribose
What is lipids, monomer, polymer, bond, elements, example?
3 fatty acids and glycerol, no polymer, ester linkage, (C,H,O), phospholipids
What is proteins monomer, polymer, bond, elements, and example?
Amino Acids, polypeptide, peptide bond, (C,H,O,N,S), hemoglobin
What is nucleic acids monomer, polymer, bond, elements, and example?
Nucleotides, polynucleotide, phosphodiester bond, (C,H,O,N,P), DNA/RNA
What is the storage polysaccharide in plants? What is it in animals?
Plants –> Starch
Animals –> Glycogen
What are the two main structures in phospholipids?
phosphate head, 2 fatty acid tails
Where do peptide bonds form between amino acids?
Between C and N terminus
Who discovered that A%=T% and C%=G%
Erwin Chargaff
Who discovered the structure of DNA?
Watson and Crick
What are the 5 key features of DNA?
DNA runs in opposite directions, has major and minor grooves, uniform diameter, double stranded helix, right-handed helix
What was Griffith’s experiment and what did it discover?
Used mice with virulent and nonvirulent strand of bacteria to prove that there is a transforming principle
Avery discovered the transforming principle. How did he do that?
Used enzymes and observed which cells transformed, DNA was the transforming principle
The hershey-chase experiment used a virus to determine whether ___ or ______ is the genetic material
DNA, Protein
What is transfection?
Genetic information of eukaryotic cells
What did the Miller Urey experiment prove? What were the existing conditions of Earth at the time?
Earth led to the formation of amino acids, pyrimidines, and purines. Existing conditions were lightning, heated water, and combination of gases
What were Redi’s and Pasteur’s experiment? What did they prove?
Pasteur used two types of flasks to see what had microbial growth. Redi used 3 jars with meat inside and found which grew maggots inside. Both disproved spontaneous generation and proved that life only arises from life itself.
Phosphate groups in nucleic acids have what kind of charge?
Negative
Is carboxyl a strong or weak acid? Is amino a strong or weak base?
Both are weak
DNA has a 3’ and 5’ end. Which side is the hydroxyl and which side is the phosphate?
3’ = hydroxyl
5’ = phosphate
Definition of translation and transcription with respect to expression of a gene to form a polypeptide
Translation - making a single stranded RNA copy of a gene
Transcription - using RNA sequence information to make a polypeptide
Transcription requires (3 things)
DNA template
Nucleotide sequence (ATP,GTP,CTP,UTP)
RNA polymerase enzyme catalyzes the synthesis of RNA
Transcription starts at ___ and goes to ___
5’ UTR, 3’ UTR
Are UTRs introns or exons
introns
Where does translation occur
in the cytoplasm
Does bacteria have introns
No
Which way does transcription read?
5’ to 3’
What does the poly A tail cause?
Stability
What does the spliceosome cut?
pre-mRNA then it releases introns, splices exons together to produce mature mRNA
What are the two forms of Amino Acids? Which one is only in living cells?
D, L
L in living cells only
Three types of Amino Acid interactions
Amino acids with electrically charged hydrophilic side chains
Amino acids with polar but uncharged side chains
Amino acids with non-polar hydrophobic side chains
How many different things do you need to have in order to have optical isomers?
4
What is special with cysteine
has -sh which creates disulfide bridges
What is special about glycine
it has a hydrogen which makes it very small
What is special about proline?
It causes bends in proteins
4 subunits that are different are called a what?
homotetramer
Denatured or newly synthesized proteins can sometimes bind to other molecules inappropriately ________ help prevent this
Chaperone Proteins
What does rRNA do?
Catalyzes peptide bonds and provides structure
tRNA does what?
Is an adapter between the mRNA code and the amino acids used to make a polypeptide
They carry amino acids for the process of translation
Where are the anticodons located on a strand?
In the middle
What end does the covalent attachment of amino acids add on
3’
What was Benzer’s experiment and what did it do?
He found out that anticodons are recognized to make proteins by changing the tRNA when it codes for the anticodons
Do stop codons code for amino acids
No
What is redundancy?
There is more than one codon for amino acids
What does it mean when the genetic code is unambiguous?
Each codon specifies only one amino acid
What is the definition of Wobble?
When specificity for the base at the 3’ end of the codon is not always observed. For example GCA, GCG, GCC, and GCU all code for alanine.
What was Nirenberg, Matthaei and Khorana’s experiment?
They used artifical polynucleotides instead of mRNA as a messenger
Identified the polypeptide that resulted from each artificial polynucleotide
How many codons are there?
64
What is the A site?
Entry of charged tRNA; binds to mRNA
What is the P site?
Growing protein is transferred to the amino acids on the incoming tRNA
What is the E site?
Where the uncharged tRNA sits before being released
What would happen if you were to give polycistronic mRNA to a monocistronic mRNA?
It would continue coding for only one protein
A researcher has measured the pH of a solution and found that the pH is 10. This solution is ____ and has more ____ compared to ____
basic; hydroxide ions; protons
What is an abundant element found in the crust, but trace amounts in the human body?
Silicon
What are the 5 most abundant elements in the body?
C,H,O,N,P
What properties does a hydroxyl, carboxyl, amino, phosphate, and thiol functional group have?
Hydroxyl - polar
Carboxyl - acid
Amino - base
Phosphate - Negative charge, hydrophilic
Thiol - disulfide bridges
What are carbohydrates structural function in insects?
Chitin, found in insects exoskeleton
Lipids are ______________ and serve as insulation in animals, nerve coatings for electrical insulation, and prevent drying?
non polar hydrocarbons
How is DNA packaged?
Histones
DNA + Histone = Nucleosome
______________ allows for different proteins to be coded from the same gene
Alternative splicing
In the Hershey-Chase experiment, what viruses did they use?
P32 and S35
