Honors Bio Williams s2

*Role and Function: store genetic information

*Structure: Double Helix, 2 polynucleotide

Hydrogen bonds, nitrogenous base, deoxyribose sugar, phosphate group

How do cells copy DNA? - S phase, Dna unwinds

*Replication

Helicase unwinds DNA, Polymerase makes new strands

*DNA Mutations

More times a DNA replication, higher chances of mutation

Enzymes “proofread” DNA and try to correct mistakes

43 *Central Dogma of Molecular Biology - DNA>RNA>Protein

Basic framework for how genetic information flows from DNA/gene > protein

Transcription: copying a DNA gene into RNA

Translation: converting RNA into amino acids

47 *Three RNA

Messenger RNA (mRNA)

Carries genetic information from nucleus to ribosome

RIbosomal RNA (rRNA)

Peptide bonds between AAs

60% of ribosomes (where polypeptides/proteins are made)

Transfer RNA (tRNA)

Transfers amino acids in the cytoplasm to ribosomes

amino acid holding end, anticodon

49 *Post-transcriptional Modifications

1. 5’Cap: added to beginning of gene

Helps ribosomes recognize start sequence

Prevents mRNA breakdown in cytoplasm

2. Poly-A tail: added to end of gene

Helps ribosomes recognize end of gene and detach

3. Splicing: Introns removed & Exons “spliced” together

One gene = more than one protein

*What is the purpose of transcription? To make a copy of the gene to take to the ribosome for protein synthesis

Where in the cell is the DNA found? NUCLEUS

Where in the cell does transcription take place? NUCLEUS

What polymer is synthesized during transcription? mRNA

What monomers are used to construct this polymer and where are they found? NUCLEOTIDES, Inside the nucleus

What enzyme (protein that makes reactions happen) is required for transcription? RNA polymerase

79 *Nondisjunction

When homologous chromosomes fail to separate during Meiosis I or II

*Sickle Cell Disease

carry less oxygen

Hemoglobin is affected by mutation

*Gel Electrophoresis - separate dna fragments by size

enzymes added to dna to cut it

Large dna fragments are closer to start

Ch 14

Human Chromosomes - 46 chromosomes, 23 pairs

Human Pedigrees - trace inheritance genes

Human Genetic Disorders/Traits

*Blood Typing

*Sickle Cell Disease

carry less oxygen

Hemoglobin is affected by mutation

*Cystic Fibrosis (autosomal recessive)

Huntington’s Disease (autosomal dominant)

Genetic Advantages (Heterozygote Advantage)

Manipulating DNA

Restriction Enzymes - cut dna segments

*Gel Electrophoresis - separate dna fragments by size

Enzymes added to dna to cut it

Large dna fragments are closer to start

CHAPTER 11: Introduction to Genetics: Information and Heredity

11.1-11.4

Gregor Mendel’s Contribution - used the peas as an example

Segregation of Alleles - pulling apart allele

Independent Assortment of Chromosomes - random distribution of alleles

Dominance - more likely

Recessive - less likely

Alleles - version of a gene

Gene - made up of dna, controls your traits

Punnett Squares - predict the Probability of Traits

Other Patterns of Inheritance (beyond Mendelian/Complete Dominance)

Incomplete Dominance - traits are mixed

Codominance - both show up but not mixed

Multiple Alleles - more than two possibilities for a trait

Polygenic trait - human skin color

*PCR - amplify dna sequences

Pedigree chart - trace inheritance genes

Polymerase - needs taq to withstand temperature without denaturing

Alleles and genes - alleles r difference form of a gene

Meiosis and genetic diversity - increases with variety

Cystic fibrosis - autosomal recessive

Ribosome synthesize proteins

Dna negative, attach to positive

Biological fitness - ability to survive and reproduce

Recombination dna - combination of dna from 2 or more organisms, uses restriction enzymes

Gene therapy - cure genetic disorders by replacing defective genes

CRISPR - repairs existing abnormal genes

Huntington’s disease - autosomal dominant, only need one dominant

X-linked recessive disorders - common in males