Bio 111 Midterm 2

Nucleotide

Sugar-phosphate backbone + nitrogen containing base

Base Pairs

A - T, G - C , connected by hydrogen bonds

Chromosome

2 chromatids connected by a centromere

Coiled DNA around histones (Nucleosome), then into beads on a string, and finally the fiber

Genome

An organism's complete set of DNA

Gene

A specific sequence of DNA bases

Locus

The location or position of a gene on a chromosome

Alleles

Different versions of a gene that code for the same trait.

Coding Vs. Non-Coding

Exons: Regions of DNA that code for protein.

Introns: Regions that are not used.

Genotype

The organism's genetic composition. (AA, Aa, aa)

Phenotype

The physical manifestations of the instructions

Central Dogma

DNA -> RNA -> Protien

Transcription

The genes sequence is copied from DNA to mRNA. Happens in nucleus.

Translation

mRNA—produced by transcription from DNA—is decoded by a ribosome to produce a specific amino acid chain, or polypeptide.

Process of Transcription

Once RNAp sees a promoter on a strand of DNA (gene) it begins reading it, RNAp makes an RNA strand copy of this sequence, when RNAp recognizes the end of the gene it releases the mRNA, a cap and tail are added for protection.

Process of Translation

A free tRNA finds a start codon on mRNA and a ribosome group fits on to the tRNA, tRNA translates codons by linking with specific codons, free amino acids attached to tRNA begin to form a protein chain as the ribosome moves, happens until a stop codon.

Microarrays

A tool used to monitor the expression levels of thousands of genes simultaneously. Useful in how gene expression differs in response to illness.

Gene Control: Promoter

Promoter: Region of DNA that RNAp recognizes and binds to in order to produce an mRNA transcript of the genes.

Gene Control: Operator

Operator: Region of DNA that a repressor protein can bind to, thus blocking RNAp from transcribing

Gene Control: Regulatory Gene

Regulatory Gene: Genes located within the operon that code for repressor proteins that impede transcription.

Lac Operon

Lactose: Lactose binds to the repressor protein preventing it from binding to the operator; this allows the RNAp to start transcribing.

No lactose: The repressor protein binds to the operator, preventing RNAp from binding to the promoter and transcribing.

Mutation

Alteration of the sequence of bases in DNA.

When does the RNA operator bind

In the absence of lactose.

Types of Mutation

Insertion

Deletion

Substitution

Mutation to Illness

A mutated gene codes for a non-functioning protein.

Fast Flush, Tay-Sachs Disease

Biotechnology

Adding, deleting, or transplanting genes from one organism to another.

Biotech: Chop

The segment of DNA is located, a restriction enzyme is introduced that targets base pairs on the sides of the segment, the enzyme binds to the ends and cuts the DNA

Biotech: Amplify

The DNA segment is heated to separate the double strand

DNAp, cold, and free nucleotides are added

DNAp adds complementary base pairs to the 2 strands; this doubles the DNA segment

Biotech: Insert

Chop is executed on a segment in a bacterial plasmid, the desired DNA segment is now on the plasmid, the plasmid is inserted back into the bacterial cell

DNA Probe

Bacteria a exposed to a wash that breaks down DNA into single strands, a radioactive probe washes the single strands, this wash contains a short length of DNA that contains a sequence of bases complimentary to the gene of interest.

Biotechnology Examples

Golden Rice, Insect Resistance,

Insulin

Made by recombinant DNA technology

Pompe Disease

Cannot synthesize glycogen enzyme

Gene Therapy

Biotechnology helping diagnose and preventing diseases

Telomere

A protective cap at the end of the DNA on chromosomes. Each time a cell divides, the telomere gets shorter.

Cancer

Telomeres do not shorten or age, and divide indefinitely.

Prokaryotic Cell Division

Binary Fission (Asexual): A replication of the DNA and a cloning of the parent cell to create an exact replica.

Somatic Cells

All cells except sex cells.

Eukaryotic Cell Cycle

Interphase and Mitotic Phase

Interphase

Gap 1, S Phase, Gap 2

Mitotic Phase

Mitosis, Cytokinesis

Gap 1

Is the DNA damaged, does the cell have sufficient nutrients, normal growth phase

S Phase

Begins preparation for division. Chromosomes create duplicates

Gap 2

Has the DNA replicated properly, second period of growth

Sugar-Phosphate Backbone

1' = Base connection

3' = Hydroxyl connection

5' = Phosphate connection

DNA synthesis goes from 5' ---> 3'

DNA Replication

Unwinding/ Separation: DNA Helicase

Reconstruction/ Elongation: An RNA primer attaches compliment bases, DNAp then adds the DNA and later replaces the primer with DNA

Chromatids

After replication, each chromosome appear as linear DNA molecules held together by a centromere

DNA Strand Synthesis

While the leading strand is fully complimented, the lagging strand is only complimented in segments

Mitosis

Inter, Pro, Meta, Ana, Telo/Cyto

Mitosis Steps: Prophase

Nuclear membrane breaks down, Sister chromatids condense, Spindle forms

Mitosis Steps: Metaphase

Sister chromatids line up at the center of the cell, attaching to the spindles

Mitosis Steps: Anaphase

Sister Chromatids are pulled apart by spindle fibers.

Mitosis Steps: Telophase

Chromosomes begin to uncoil as the nuclear membrane reassembles, Cell begins to split.

Sex Cell Division

Gametes: Cells with half of the chromosomes

Diploid: 2 copies of each

Haploid: 1 copy of each

Meiosis:

Starts with diploid cells. Reduces the amount of genetic material in gametes by half.

Produces gametes that differ, 4 haploids.

Homologues

Maternal and paternal copies of a chromosome.

1-23 Chromosome, 24 = sex cell

Meiosis: Interphase

The Chromosomes replicate, enter Pro 1.

Meiosis: Prophase 1

Chromosomes condense.

Spindles form.

Homologous pairs of sister chromatids come together.

Nuclear membrane disintegrates.

Cross over occurs

Meiosis: Metaphase 1

Homologues move towards the center of the cell and line up.

Meiosis: Anaphase 1

Homologues are being pulled apart

Meiosis: Telophase 1 and Cytokinesis

Chromosomes at both spindles. Cell splits into 2 daughter cells, enter Pro 2

Outcome of Meiosis

Goes through pro, meta, ana, telo agian but with the sister chromatids being pulled apart instead of homologous. Resulting in 4 haploids

Cross Over

This occurs between the paternal and maternal sister chromatids when they swap info during Pro 1.

Flow of genetic Info

Transcription, mRNA processing, Translation (Cytoplasm)

Codon

3 based sequence in mRNA

Human Sex

Females = XX, Males = XY

Chemotherapy

Prevents spindles from forming

Family Resemblance

Your mother and father contribute equally to your genetic makeup.

FM03

Fish odor syndrome, an enzyme cannot be broken down and is excreted

Mendel's Pea Plants

Easily categorized traits, Repeatedly breed plants resulting in unvarying results

Law of Segragation

Only one of the two alleles for a gene is put into a gamete. At fertilization, offspring receive from each parent one allele for each gene.

Heterozygous

Two different alleles for the same gene.