Molecular quiz chapters 1, 2, half of 3

Inheritance

Its in the blood"
- DNA mediates
- The acquisition of characteristics, qualities or traits by the transmission of genes from parent to offspring.

Prokaryotic

Contain one continuous space in which cellular materials are organized, but separated by membranes.
- All have cell walls
- Lack nucleus -- has nucleoid
- Usually single-celled
- Include both bacteria and archaea --> (live in extreme environments)

Eukaryotic

Contain sub-cellular compartments. A membrane surrounds each compartment.
- Usually 10-100 fold larger than prokaryotic cells
- Both single celled and multi-cellular organisims
- Plants are only surrounded by a cell wall
- contains nucleus and organelles

Organelles

Membrane bound compartments with distinctive morphology and function present in the cytoplasm of all eukaryotic cells

Nucleus

Home to the vast majority of DNA, where it is complexed with proteins and enclosed within a double membrane (nuclear envelope) and contains all the chromosomes and one or more nucleoli (site of ribosome assembly)

Nucleoid

A prokaryotes DNA is tightly coiled with proteins in this region and is not membrane bound.

Ribosomes

Very large multi-protein-RNA complexes that perform protein synthesis (translation) in the cell.
- Both eukaryotic and prokaryotes have

Cytoplasm

The watery interior environment of cell.

Traits

Genetically determined chacteristics and phenotypes exhibited by an individual

Dominance

A gene that directs a phenotype even when present at only one copy per cell

Recessive

Phenotypic expression of a genetic allele only in homozygous cells that lack wildtype forms of the gene.

Genes

Biological genetic units of heredity

Chromosomes

colored bodies"
Threadlike strands of chemical material located in the cell of nucleus.
- Structures in the cell nucleus that each contain one linear double-stranded DNA molecule.

Deoxynucleic acid (DNA)

Nucleic acid polymer of bases which make up the genes.
- First named nuclein

Zygote

The cell resulting from the union of a male and a female gamete during fertilization

Transforming substance

In early experiments, DNA was found to change (transform) the biochemistry of bacterial cells

Cell-free extract

Subcellular fraction created in vitro that retains biological activity.

Enzyme

A protein that acts as a catalyst, increasing the rate at which a chemical reaction occurs, without itself changing in molecular shape.

Segregation- Mendel

two alleles for a single trait separate during gamete formation

Independent assortment- Mendel

different traits are inherited separately

Dominance - Mendel

one allele can mask another

Wrinkled vs. Smooth seeds

insertion mutation- gene for starch synthesis- chromosome 5

Yellow vs. Green seeds

insertion or substitution- 'stay-green' gene (activates chlorophyll breakdown)- chromosome 1

Flower color (seed coat color)

intron-splicing mutation- transcription factor controlling a gene for anthocyanin synthesis- chromosome 2

Tall vs. Short plants

insertion- gene for gibberellin synthesis (a hormone that makes plants grow taller)- chromosome 3

Green vs. Yellow Pods

2 loci- linked traits- chromosome 5

Gregor Mendel

Developed the basic principles of genetics

Thomas Hunt Morgan

Showed that inheritance is due to chromosomes

Miescher/Feulgen/ Mirsky

Showed that inheritance is due to the DNA (not protein) in chromosomes

Griffith/Alloway/Avery

Showed that functional DNA could be extracted from one bacteria and placed into another bacteria

Hershey/Chase

Showed that DNA is responsible for viral replication.

DNA Polymerase

An enzyme that copies DNA templates into new DNA strands when chromosomes are being replicated

Primers

A short RNA or DNA strand that is base paired to the template DNA strand at the position on the helix where DNA replication takes place.

DNA ligase

Enzyme that catalyzes the formation of a covalent chemical bond between the 3' and 5' ends of two DNA strands, sealing the DNA backbone and joining DNA fragments end to end.

3' to 5' proofreading exonuclease

Enzymes that cleave single mononucleotides from the 5' to 3' end of the DNA strand

Orgin of Replication

Site on a DNA molecule where DNA replication begins (initiation)

Nanotechnology

Technology dealing with structures smaller than 100 nanometers in size and involves developing materials or devices with novel properties; the technology of molecular manufacturing outside the cell, including molecular machinery inside the cell.

Bases

Alkaline chemical substances; in molecular biology refers to the cyclic nitrogen compounds found in DNA and RNA.

Adenine

A PURINE base found in the DNA and RNA nucleic acids of cells in plant and animal cells.

Thymine

A PYRIMIDINE base found in DNA but... NOT RNA

Guanine

One of the five fundamental bases that make up DNA and RNA sequences. PURINE

Cytosine

a PYRIMIDINE base in DNA and RNA

Uracil

A PYRIMIDINE base found in RNA but.. NOT DNA

Purines

heterocyclic aromatic organic molecule

Pyrimidines

Type of nitrogenous base with a single chemical ring found in DNA and RNA

Nucleotides

The monomer component of a nucleic acid (DNA or RNA), consisting of a PENTOSE sugar plus a base and a phosphate group.

Polarity

In DNA this refers to the two chemically different ends of each DNA strand called 3' and 5'.
In the helix, the two DNA strands are arranged in opposite directions: 5' to 3' and 3' to 5'.
In cell development, polarity can refer to the different biological

Antiparallel

DNA strands with polarity (5' to 3') are arranged in opposite directions in the DNA helix molecule.

5' to 3' direction

Starting at 5' end of a DNA strand and reading toward the 3' end of the same DNA strand.

X-ray diffraction

A process in which crystallized molecules are rotated and bombarded with x-rays to determine structural information about the molecule.

Transcription

Process by which genetic information in DNA is copied into an RNA transcript.

E. coli DNA Polymerase I

one of three enzymes that replicate DNA in E. coli

Monomer

A protein molecule of a relatively low molecular weight that can bind to itself and other proteins to form dimers, trimers, or other protein complexes, sometimes bound to DNA or RNA.

Multiprotein

Consisting of several proteins that interact together in a complex.

Replication fork

The region of a replicating DNA that encompases half of a replication bubble
- Contains replicating DNA and the enzymes and other proteins involved in DNA synthesis.

Leading strand

The strand of DNA that is synthesized continuously during DNA replication and DOES NOT contain Okazaki fragments.

Lagging strand

The DNA synthesized in short single-strands called Okazaki fragments during discontinuous DNA replication.

Helicase

An enzyme that unwinds the DNA double helix at each replication fork

Continuous replication

mechanism of DNA replication used to synthesize the leading strand of DNA at each replication fork

Discontinuous replication

mechanism of DNA replication used to synthesize the lagging strand of DNA at each replication fork

Primase

Enzyme that participates in DNA replication by making RNA primers needed to initiate DNA replication.

Okazaki fragments

short single-stranded DNA synthesized on the lagging strand during DNA replication

Origin of replication

short DNA sequences where proteins help to unwind the double-helix

Molecular structure of DNA

5' --> 3', sugar phosphate backbone with phosphodiester bond, 5' end is nonpolar with phosphate group exposed, 3' end is polar with exposed hydroxyl group for next base to attach to, A and T two hydrogen bonds, C and G three hydrogen bonds

How do you recognize individual DNA nucleotides that combine to form a longer DNA molecule

pentose 5C sugar with -OH at carbon 3

Phoebus Levene

Described the chemical 'building blocks' of DNA and RNA

Erwin Chargaff

Discovered that the amount of adenine in DNA was equivalent to the amount of Thymine and the amount of cytosine was equivalent to the amount of guanine

Rosalind Franklin

Performed crystallography and x-ray diffraction of DNA

Watson/Crick

Determined the 3-D structure of DNA

Meselson/Stahl

Showed that during DNA replication, both original strands serve as templates for making new strands. (Semi-conservative replication)

Arthur Kornberg

Isolated functional DNA polymerase from bacteria

DNA replication

5' to 3' direction, DNA polymerase, DNA ligase

Figure 2.26

DNA --> RNA --> protein

Genetic Screen

A method to search for rare cells using the genetic characteristics of the cells.

Mutation

Change in a DNA or RNA sequence

Mutagen

An agent that induces genetic mutation by changing DNA sequence.
(For ex: a "G" changed to a "T")

One gene-one enzyme hypothesis

The early idea that each gene in a cell can produce only one specific protein or cellular enzyme.

Amino acid

any of a class of organic compounds containing amino (NH2) and the carboxyl (COOH) groups, forming the main constituents of protein

Protein synthesis

The production of proteins by the process of TRANSLATION in cells.

Codons

3 consecutive RNA or DNA bases that encode a single amino acid

Genetic Code

The sequence of tandem nucleotide triplets (codons) in DNA or RNA that specifies the aa sequence of a protein.

Central Dogma

DNA --> Transcription --> RNA --> Translation --> Protein

Beadle/Tatum

wanted to induce mutations that affect its ability to make essential vitamins or amino acids, used x-rays. Then grew it on enriched media which includes all vitamins and amino acids that it would need. E2 is not functional

Single mutation leading to sickle cell anemia

146th amino acid is changed from glutamic acid (normal) to valine (mutant)

Bacteriophage

viruses that infect bacterial cells

How does bacteriophage reproduce?

DNA genomes enter the cells, the bacteria synthesize the bacteriophage RNA before they begin synthesizing protein

Figure 3.17

genetic code table- first, second, and third bases in codon make a single protein

How is protein sequence determined from DNA sequence?

3 consecutive RNA bases encode a single amino acid which together form a protein linked with a peptide bond