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Review:
Chapter 1: Concepts in Biology
Unifying themes in biology:
*Organization
atoms-molecules-organelles-cells-tissues-organs-organism
*Cells-basic unit of structure and function
Cell theory – all living things consist of cells
*Science is a process: 1) discovery 2) hypothetico-deductive
Chapter 2: Chemical context of life
*element- fundamental types of matter that cannot be split
into other stable entities
*atom – the smallest identical particles into which matter
can be divided
neutrons-protons-electrons
energy levels of electrons – determines chemical behavior
*covalent bond – sharing a pair of valence electrons by two atoms
*ionic bonds – attraction of cations and anions
Review:
Chapter 2: Chemical context of life, con’t
*molecule – two or more atoms held together by covalent bonds
*compound – two or more different elements combined
Hydrogen bonds:
between hydrogen atoms covalently bound to electronegative atoms
δ +
δ δ +
δ -
δ +
Chapter 3:
δ +
Properties of water
δ +
*Polarity of water results in hydrogen bonding
*Water moderates temperatures on Earth
*Water is the solvent of life
*Hydrophilic and hydrophobic substances
*Acids, bases and pH
Review:
Chapter 4: Carbon and the molecular diversity of life
Importance of Carbon
*Organic chemistry is the study of carbon compounds
*Carbon atoms are versatile building blocks of molecules
*C-skeletons contribute to diversity of organic molecules
Functional Groups
*Functional groups contribute to molecular diversity of life
Chapter 5: Structure and function of macromolecules
Macromolecules are polymers
Carbohydrates – fuel and building material
*sugars and sugar polymers
Lipids – diverse hydrophobic molecules
*fats, phospholipids and steroids
Proteins – many structures and functions
*polymer of amino acids – function depends on conformation
Nucleic acids – informational polymers
*store and transmit genetic information
Review:
Chapter 6: Intro to Metabolism
Metabolism – an organisms complete set of chemical reactions
*catabolism – degradative
*anabolism - synthetic
Chemical reactions with free energy changes:
*exergonic – “energy outward” *endergonic – “energy inward”
net release of free energy
absorbs free energy
Chapter 6: Intro to Metabolism
*Enzymes are catalytic proteins – change the rate of reaction
without being consumed by the reaction
Enzymes lower the barrier of EA:
Physical and chemical properties
affect enzyme activity:
*Temperature
*Enzyme concentration
*pH
*activators and inhibitors
Review of cell ultrastructure:
*Generalized animal cell
Not in animal cells:
chloroplasts
central
vacuole/tonoplast
cell wall
plamodesmata
*Generalized plant cell
Review:
The Cytoskeleton
Functions include:
*structural support
*cell motility
*reg of biochemical activities
Consists of:
*microtubules
*microfilaments
*intermediate filaments
Cell Surfaces and Junctions
*Plant cells have cell walls
*Extracellular matrix (ECM)
Collagen Proteoglycans Fibronectin Integrin
Cell Surfaces and Junctions
*Intercellular junctions
Tight Junction Gap Junction Desmosomes
Membranes
*Fluid mosaic model
Traffic across membranes
*passive transport
*active transport
Diffusion
Active transport
Facilitated diffusion
CH 9: Cellular Respiration
Cellular Respiration – #1 pathway in ATP production in which oxygen and
other organic fuels are consumed
SUMMARY:
Organic + Oxygen
Compounds
C6H12O6 + 6 O2
Carbon + Water + Energy
Dioxide
6 CO2 + 6 H2O + energy
Redox reactions release energy
Redox reaction (oxidation-reduction) – chemical reaction involving the
transfer of one or more electrons from one reactant to another
*loss of an electron = oxidation
*gain of an electron = reduction
3 metabolic stages:
*glycolysis
harvests chemical energy by oxidizing glucose to pyruvate
*Krebs cycle energy-yielding oxidation
*electron transport ATP synthesis
chain and oxidative
phosphorylation
Fermentation enables cell to produce ATP w/o O2
CH 10: Photosynthesis
SUMMARY:
6CO2 + 12H2O + light energy
C 6H12O6 + 6O2 + 6H2O
*Light reactions – convert solar energy to chemical energy, etransferred to NADP +, water is split, O2 by-product
*ATP generated via photophosphorylation
*Calvin cycle – carbon fixation, reduce CO2
Light reactions:
Calvin cycle reactions:
*carried out by
molecules in thylakoid
membranes
*convert light energy
to chemical energy
*split H2O and
release O2
*take place in the
stroma
*use ATP and NADPH
to convert CO2 to G3P
*return ADP and
NADP + to the light
reactions
CH 12 and 13: Cell cycle, Mitosis and Meiosis
*Cell division is a part of the cell cycle
Mitosis - a process of nuclear division which results in the
formation of two new nuclei each having the same number of
chromosomes as the parent nucleus
Late Interphase
*chromosomes & centrosomes duplicated
*begin microtubule organization
Prophase
*chromosome coiled; *nucleoli disappear
*mitotic spindle form
Prometaphase
*nuclear envelope fragments;
*microtubules attach to chromosomes
*spindle push chromatids
Metaphase
*chromosomes align along central plane
Anaphase
*centromeres divide
*sister chromatids separate
Telophase
*cell continues to elongate; *two nuclei form;
*chromatin uncoils *cytokinesis
Meiosis - cellular process that results in the number of chromosomes
in gamete-producing cells being reduced to one half
Late Interphase
*chromosomes & centrosomes duplicated
*begin microtubule organization
Prophase I
*chromosomes condense;*homologous chromosomes
form tetrads during synapsis
Metaphase I
*tetrads align along central plane *microtubules
attach to kinetochores
Anaphase I
*homologous pairs of chromosomes separate
Telophase I
*two haploid cells form;*chromosomes are still double
Meiosis II
*phases very similar to mitosis
CH14: Mendel and the gene idea
*particulate inheritance – parents pass on discrete heritable units
*gene- unit of inheritance which occupies a specific chromosomal location (locus)
*allele- alternative forms of a single gene
Mendel’s hypothesis (to explain his results)
1. Alternative versions of genes (alleles) account for variation in
inherited characters
2. For each character, an organism inherits two alleles, one from
each parent
3. If two alleles differ, then one (the dominant allele) is fully
expressed in the organism’s appearance; the other (the recessive
allele) has no noticeable effect on the organism’s appearance.
4. The two alleles for each character segregate (separate) during
gamete production.
*genetic make-up – genotype
*appearance - phenotype
*Homozygous – 2 identical alleles for a character
*Heterozygous – 2 different alleles for a character
Modifications of Mendelian Ratios
*Incomplete dominance
*Codominance
*Multiple Alleles
*Pleiotropy
*Epistasis
CH15: The Chromosomal basis of inheritance
*Chromosomal theory of inheritance
*Sex Chromosomes
Sex chromosomes- chromosomes involved in sex determination
Autosomes- non sex determining chromosomes
replication
*Sex-linkage
X-linkage- transmission and expression of
genes located on the X chromosome
*The X Chromosome and Dosage Compensation
CH 16: The Molecular Basis of Inheritance
*DNA as the Genetic Material
Griffith – “transforming principle”
Hershey and Chase – DNA
Review con’t:
*Structural analysis of DNA
Composed of nucleotides – phosphate, deoxyribose, nitrogenous base
Strands are antiparallel and complementary
Double helix
*Mode of DNA Replication
Semiconservative
*Overview: DNA replication
*Complementarity determines which nucleotide will be added
*Chain elongation in a 5’-to-3’ direction
1) Strands must separate
•Helicases unwind helix
•SSBPs prevent closure
•DNA gyrase reduces tension
2) Primase synthesizes short RNA primer
3) DNA synthesis by DNA polymerase
4) Primer removal and replacement with DNA
(by a different DNA polymerase than step 3)
5) Ligase closes up the gaps b/w Okazaki
fragments
*Overview: Transcription
1) Transcription factor binds to TATA box of promotor
2) RNA polymerase and additional transcription factors bind promotor
3) RNA synthesized by RNA polymerase
4) Transcription continues until RNA polymerase reaches terminator
*Overview: Translation
1) Association of large and small ribosomal subunit, mRNA, initiator
tRNA; GTP required; initiator tRNA binds to P site
2) “Charged tRNA” enters A site, requires GTP
3) Peptide bond formation
4) Translocation (peptidyl tRNA transferred to P site, uncharged
tRNA removed from ribosome) requires GTP
5) Steps 2-4 repeat
6) Termination factor binds STOP, disassembly of complex