Module 31 Flashcards
Gene Expression and Regulation
Where do cells store information
DNA
What do cells uses DNA/ information for
identity, function, and sustain life
How do all cells transmit information
Cell division
-Mitosis and meiosis
Cell cycle
Cell grows, copies chromosomes, and divides through mitosis.
How do sexually reproducing cells transmit traits
Inheritance
Mitotic cell division,
Nucleic Acids
Informational molecules
-DNA, RNA
In what form do nucleic acids carry information
Nucleotides
What do the nucleotides within DNA code for
Amino acid sequences for proteins
RNA function
Gene expression
Protein synthesis
What type of bonds hold nucleotides together
covalent
Nucleotide structure
5-carbon sugar
nitrogen base
phosphate group
Nucleic acids building block
Nucleotides
Sugar in DNA
Deoxyribose
H at 2nd carbon
Sugar in RNA
OH at 2nd carbon
Pyrimidine Bases
Rings, H-bonds, and bases
Single Ringed
T, C, U
3 H-bonds
Purine Bases
Double-Ringed
A, G
Phosphodiester Bonds
What are they
What part of DNA do they form
Form between a phosphate group of one nucleotide and the sugar of another nucleotide
Form the sugar-phosphate backbone of DNA
What kind of bond are phosphodiester bonds
Covalent Bonds
What base pairing makes 2 Hydrogen Bonds
A-T
What base pairing makes 3 Hydrogen Bonds
G-C
What is base pairing a result of
hydrogen bonding between nucleotide bases
How is DNA so various and able to carry genetic info for so many spieces
There is no restriction to a nucleotide sequence within the DNA strand
How is genetic information encoded within DNA molecules
Throughout the sequence of bases
Where do cells come from
Preexisting cells
Functional unit of life
Cell
DNA Replication
What is and purpose
Process of duplicating DNA
Allows genetic information to be passed from cell to cell AND from organism to progeny
Progeny
Offspring
How do we know that replication evolved early in life’s history
It occurs in virtually the same way for all organism
What allows DNA to be stably and reliable passed down from generation to generation
The structure
Each parental strand serves as a template for the daughter cell
Corresponding base pairs
Mutations cause
Environmental insults (radiation, carcinogens)
Accidents by Polymerase
Protein functions
Enzymes, channels, transporters, structural support
What determines a protein function or how they fold
Their amino acid sequence
DNA determines amino acid sequence
What is a proteins amino acid sequence determined by
DNA
The Central Dogma
A theory that describes the pathway of information from DNA –> RNA –> Protein
Basic flow of information in a cell
Transcription
The process where DNA is used to build an RNA molecule
They are copied using nucleotides
What language is used when transcribing
Nucleotides
Translation
Process where protein is synthesized from RNA
What language change happens during translation
Nucleotide to amino acid
How much of a DNA molecule is used to make a protein
ONLY a segment
A Gene
Gene
A DNA segment sequence that corresponds to a specific product, like a protein
Exceptions to the flow of information
HIV- flows in reverse
Flu replication- RNA to RNA
Gene Expression
The process by which a gene is transcribed and transferred
When are genes turned on / expressed
When a gene produces a protein
Gene Regulation
4 parts
The process that controls if, when, where, or for how long a gene is expressed
Housekeeping Genes
Genes that are expressed almost all of the time
-metabolism
How does cell specification occur
Through gene regulation
Muscle cells express genes that encode proteins that cause muscle contractions.
Noncoding RNA
RNA is not translated because they don’t code for proteins
What CAN noncoding proteins do
Help in translation, catalytic activity, act as enzymes
Where does transcription and translation occur in Eurkayotic cells
Transcription in the nucleus
Translation in the cytoplasm
Where does transcription and translation occur in Prokaryotic cells
In the cytoplasm
Why is each step of protein synthesis well-regulated in eukaryotes
Time and Space from nucleus to cytoplasm
Chromosome differences between prokaryotes vs eukaryotes
Prokaryotes have one circular chromosome in each cell while Eukaryotes have multiple (23 pairs in humans) linear chormosomes
Chromosomes
Structure within each cell that is made up of a single DNA strand, associated with proteins
How are chromosomes passed from cell to cell
They replicate and pass during cell division
Prokaryotic cells divide by binary fission
Eukaryotic cells divide by mitosis and cytokinesis
Chromosomes purpose
A way to package long DNA molecules
Problem with circular chromosomes and base pairing
Not enough pair, because it makes fewer turns, resulting in a strain
Supercoils
DNA molecules coil on itself
Relieves the strain on DNA, allowing base pairs to form
Prokaryotic cells only
Nucleoids
DNA structure with multiple loops/ supercoils
What binds supercoils together/ forms loops in prokaryotic DNA molecules
proteins
What compresses DNA molecules into compact circles in prokaryotes
supercoiling and protein binding that form the loops
Plasmid
Additional DNA within prokaryotes in the form of circles
Replicate independently from main DNA
Purpose of the plasmid
Not essential for survival
Helps with survival and reproduction under specific environmental conditions.
Chromatin
The DNA-protein complex within Eukaryotic cells
How DNA is packaged in Eukaryotic cells
Histone Proteins
Evolutionary conserved
DNA winds up around these proteins
Nucleosomes
How histone proteins are organized within eukaryotic cells
Rich in lysine and arginine (amino acids)
The first level of DNA packaging
“Beads on strings”
Nucleosomes are the beads and DNA is the string
DNA winds around nucleosomes, forming the chormatin
What forms the chromatin
Nucleosomes
Eukaryotic cells
Chromosome condensation
The progressive packaging and condensing of shorter, thicker chromosomes (the chromatin)
Active, energy-consuming process
Chromosome Scaffold
Supporting protein structure within chromosomes
Relationship between gene expression and gene regulation
It regulates protein synthesis/ function
When, where, if, and for how long a gene is expressed
Four Bases of DNA Sequence
Cytosine, Thymine, Guanine, Adenine
