DNA (deoxyribonucleic acid)
stores the genetic information of an organism and transmits it from one generation to another
RNA(ribonucleic acid)
translates the genetic information contained in DNA into proteins needed for all cellular function, assist in protein formation, and other biological functions
What is the monosaccharide of RNA?
aldopentose D-ribose
What is the monosaccharide in DNA?
aldopentose D-2-deoxyribose
(no OH at C2)
cytosine
Uracil
Thymine
Adenine
Guanine
Nucleoside
formed by joining the anomeric carbon of the monosaccharide with a N atom of the base
Nucleoside formation
by adding a phosphate group to the 5'-OH of a nucleoside
Phosphodiester linkages
bond that joins nucleotides together
Polynucleotide
has one free phosphate group at the 5' end and one free OH group at the 3' end
How many hydrogen bonds form an A-T bond?
2
How many hydrogen bonds form a C-G bond?
3
Replication
the process by which DNA makes a copy of itself when a cell divides
Transcription
ordered synthesis of RNA from DNA; the genetic information stored in DNA is passed onto RNA
Translation
synthesis of proteins from RNA; the genetic information determined the specific amino acid sequence of the protein
What direction does replication occur on the template strand
3' to 5'
Messenger RNA
carries the information from DNA to the ribosome
Transfer RNA
brings specific amino acids to the ribosomes for protein synthesis
What direction are codons written?
5' to the 3' end of the mRNA molecule
Silent mutation
changes a letter but still produces same amino acid
Virus
is an infectious agent consisting of a DNA or RNA molecule that is contained within a protein coating
Vaccine
an inactive form of a virus that causes a persons immune system to produce antibodies to the virus to ward off infection
Retrovirus
virus with an RNA core
What do retroviruses do
invade a host and then synthesize viral DNA by reverse transcription
Recombinant DNA
synthetic DNA that contains segments from more than one source
3 key elements are needed to form recombinant DNA
1. A DNA molecule into which a new DNA segment will be inserted
2. An enzyme that cleaves DNA at specific locations.
3. A gene from a second organism that will be inserted into the original DNA molecule
PCR (polymerase chain reaction)
amplifies a specific portion of a DNA molecule
Four elements are needed to amplify DNA by PCR
1. The segment of DNA that must be copied
2. Two primers-short polynucleotides that are complementary to the two ends of the segment to be amplified.
3. A DNA polymerase enzyme to catalyze the synthesis of a complementary strand
4.Nucleoside triphosphates-the source of the A,T,C, and G needed to make the new DNA
Catabolism
breakdown of large molecules into smaller ones; energy is generally released during catabolism
Anabolism
synthesis of large molecules from smaller ones; energy is generally absorbed during anabolism
The thioester acetyl CoA is formed..
When an acetyl group reacts with the sulfhydryl end of coenzyme A
The citric acid cycle is based in the...
mitochondria
The cycle also...
produces energy stored as a nucleoside triphosphate and the reduced coenzymes
Phosphorylation
is the reverse reaction, where a phosphate group is added to ADP forming ATP
Curved arrows
are often used to depict reactions that use coenzymes as oxidizing agents
L amino acids
means NH3 is on the left
D amino acids
means NH3 is on right
Zwitterion
-since amino acids contain a base(NH2) and an acid(COOH), a proton transfers from the acid to the base to form a...
when the pH< isoelectric pH
the carboxylate anion gains a proton, and the amino acid has a NET POSITIVE CHARGE
when the pH>isoelectric pH
the ammonium cation loses a proton, and the amino acid has a net negative charge
Peptides
are formed when amino acids are joined together by amide bonds
Dipeptide
has two amino acids joined together by one amine bond
amino acid with the free-NH3 is the N-terminal amino acid and is written on the
left
the amino acid with the free-COO- group is the C-terminal amino acid is written on the
right
Secondary Structure of proteins
-3D arrangement of localized regions of a protein
-alpha helix and beta pleated sheets
Tertiary Structure of proteins
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Quaternary structure of proteins
shape adopted when 2 or more folded polypeptide chains come together into one complex
Fibrous proteins
are composed of long linear polypeptide chains that are bundled together to form rods or sheets
Globular proteins
are coiled into compact shapes that are water soluble
alpha-Keratins
are the proteins found in hair, hooves, nails, skin and wool
Collagen
requires 3 chains in a superhelix
Denaturation
changes the 3D structure of a protein without breaking the amide bonds that form the primary structure
What can disturb the non-covalent interactions in a protein?
high temperature, acid, bas, and agitation
Cofactor
a metal ion or an organic molecule needed for an enzyme-catalyzed reaction
lock and key model
states that the active site is the rigid cavity; to react, the substrate must exactly match the shape of the active site
The induced-fit model
states that the active site has a flexible shape, which can adjust to fit a variety of substrate shapes
Noncompetitive inhibitor
bonds to the enzyme, but not to the active site
Competitive inhibitor
has a shape and structure similar to the substrate, so it competes with the substrate for binding to the active site
Zymogens
are an inactive form of an enzyme that can be converted to the active form when needed
ACE
causes blood vessels to narrow, increasing blood pressure
ACE inhibitors
are given to those with high blood pressure to prevent ACE's synthesis from its zymogen
Anaerobic respiration:Pyruvate
becomes an electron acceptor; reduced to lactate
Citric Acid Cycle
acetyl CoA is oxidized to CO2
-produces energy stored as a nucleoside triphosphate and the reduced coenzymes
To name a nucleoside derived from a pyrimidine(T,C)
use the suffix -idine (cytosine--> cytidine)
To name a nucleoside derived from a purine base
use the suffix -osine (adenine--> adenosine)
Ribosomal RNA
found in the ribosomes in the cytoplasm