Genetics

Polymer composed of nucleotides

Phosphate group, ribose sugar, nitrogenous base

Phosphodiester bond

A condensation reaction in which a ribose sugar loses a hydroxide molecule and a phosphate group loses a hydrogen atom. An excess water molecule forms.

Ribonucleotides have one more oxygen atom than deoxyribonucleotides on the pentose sugar

Purines: adenine and guanine, have two smaller rings Pyrimidines: thymine and cytosine, haev lone, larger rings

Replaces thymine in RNA

Single pentose sugar

Pentose sugar + one/two/…phosphate groups

Adenine pairs with thymine; guanine pairs with cytosine

The location of hydrogen bonds create an energetically stable arrangement: purine to pyrimidine

Double helical. Double stranded and antiparallel: one 5’ to 3’, other 3’ to 5’.

Used X ray crystallography; shot X rays at DNA, scattering and creating a pattern on a plate, creating an image. Discovered that DNA forms a helix, is double stranded, with phosphate molecules stick out.

Used Franklin’s work to discover the double helix structure, suggesting possible mechanisms for replication

Categorized as nucleotides, compoased of C, H2, O2, N2 and P, can be DNA, RNA, ATP, coenzymes, responsible for forming genetic materials, energy carriers and enzyme assistants.

• Helicase disrupts hydrogen bonds long enough to unzip the strands, creating the replication fork. It moves along the strand until complete separation • Single strand binding proteins prevent reannealation. and come off once they’re no longer needed • The toposiomerase/gyrase releases torsional tension ahead of the replication fork to release torsional tension • DNA polymerase builds the new strand of DNA by catalyzing the production of phosphodiester bonds • A nucleoside triphosphate comes in; the bond between 2 phosphates broken, releasing energy, gets transferred to make the bond between a P group and a carbon from another nucleotide -> monophosphate • DNA Pol III links the nucleotides in the leading strand with phosphodiester bonds • As more is built, more is unzipped • For the lagging strand, DNA Pol III cannot build from 3’ to 5’, so it moves away from the fork, builds, then leaps back to strart with a new segment • The primse builds RNA 10 nucleotides long, becoming the foundation (primer), needed by both the leading and lagging strand • DNA Pol I recognizes where the RNA is and replaces it with DNA • Ligase binds the Okazaki fragments together, creating phosphodiester bonds, creating one continuous strand

Create haploid cells (gametes) that can be used for sexual reproduction

Two gametes, a sperm and an ovum, each contain the haploid number of chromosomes, fuse together to form a diploid cell

Location (on a chromosome). A particular spot where protein codes for specific trait: type of info at the same spot.

Two pairs of homologous chromosomes. Sister chromatids of homologous chromosomes that line up next to each other and temporarily attach, exchanging different segments of their genetic material to form unique recombinant chromosomes

Location of crossing over

Alternate version of a gene

X: genes Y: loci Z: alleles

Prophase I: chromosomes condense, the nuclear envelope dissolve, crossing over takes place Metaphase I: tetrads move to the equator of the cell Anaphase I: homologous chromosomes are pulled to the opposite poles of the cell Telophase I: chromosomes gather at the poles, the cytoplasm divides