Girl Genius Clipboard

Saturday 9/23/06

Apparently, those who attended Friday's lecture left off with haploid and diploid cells

Haploids: sperm and egg
Diploids: all others

Steps of Meiosis (very cool, super-special eukaryotic division):

1. G1 - a pause (for suspense), preparing to replecate
2. S - growth and DNA replication
3. G2 - growth and final preparation for division
4. M - mitosis

Mitosis (Let's stick with 5 steps); cell division/reproduction

1. Interphase - Meiosis, essentially
2. Prophase - centrioles begin moving to opposite poles; spindle fibers begin extending from poles; nuclear envelope breaks apart; spindal fibers attach to centromer region chromosome
3. Metephase (this step is shorter than the last one and I like it better) - chromosomes align in middle of cell
4. Anaphase - sister chromatids are pulled apart to create daughter chromosomes; each set of daughters are pulled to opposite poles
5. Telophase - nuclear envelope appears around each daughter

Cytokinesis: divions of cytoplasm into two distinct cells

Prokaryotic Cell Division (binary fission; it even sounds gross) - asexual reproduction, producing two identical cells

Color results and the pigments they respresent (from Lab)

• Orange/Yellow-ish: beta cerotene
• Yellow: xanthrophyll
• Blue green/Green: chlorophyll A
• Olive green: chlorophyll B

I was not in class on Friday, September 22. I also did not get notes from anybody, but after all, I am awesome and a girl genius. So, here's my summation of what I think we all should have learned in my absence...

Autotrophs - produce nutrition using inorganic sources of energy (like light), and get carbon from carbon dioxide

Heterotrophs - require organic substrates for same; we're consumers

Photosynthesis (literally translated: "putting together light")

• requires light, carbon dioxide, and water
• method of grubbin' used by plants, algae, some bacteria and protists
• 6 CO2 + 12 H2O + light ---> C6H12O6 + 6 O2 + 6 H2O

Chlorophyll in photosynthesis: colors absorbed, color reflected...those are very good questions...

ATP questions that I need to work on:

• why it's the "energy currency" of the cell, and not glucose
• structure of ATP and ADP
• ATP cycle

Cellular Respiration - process of converting molecules (like, say, glucose) into useful energy; every cell technically respirates

Aerobic respiration - requires oxygen (anything else I should know?)

Anaerobic respiration / Fermentation - Some sort of definition-esque thing should go here.

• in animals and their friends - C6H12O6 --> 2 lactic acid + ATP (energy)
• in plants, bacteria and yeast, attorneys at law -
  C6H12O6 --> 2 alcohol _ 2 CO2 + ATP (energy stuff)

Okay, so my notes from this Friday totally suck and I am not a girl genius. At all. I'm just a girl who missed class and has lousy notes...and can't hide it because I've been proclaiming my meager Bio knowledge from the rooftops via the internet. Sue me.

Actually, don't sue me. Just comment and leave me suggestions, so I can stay in business. Thanks.

9/16/06 Saturday

Regarding chemical reactions...

Two outcomes for chemical reactions - release or conversion of energy

1. Release! (reactants broken down) - exergonic reaction; in the body this is catabolism (breaking macromolecules down into molecules)
2. Conversion - requires input of energy (most religious experiences do) - endergonic reaction; in the body this is anabolism (large molecules synthesized from small molecules)

Picture of ATP: http://en.wikipedia.org/wiki/Adenosine_triphosphate

ADP + P + energy --> ATP

ATP --> ADP + P + energy

^ They happen close by for each other's benefit.

Cells also need...

Enzymes - protein that acts to speed reactions by physically holding reactants together; these guys have specific active sites that they respond to surrounding molecules with. So, no square pegs in round holes.

Factors affecting enzymatic activity:

1. Temperature
2. pH - neutral for the most part, except for a cell's lysosomes (low-pH cellular garbage disposal)

9/15/06 Friday

Cell Membrane (Plasma membrane)

• No charged molecules pass through
• No macrmolecules (big dudes) get through

Fluid-mosaic model: a cell's membrane is fluid, embedded with proteins that span whole membrane or part of it

Functions of Plasma Membrane

• Protection / Concentration gradient - separates outside environment from inside
• Support - cholesterol deposits (among fatty acids in phospholipid bi-layer) stiffien membrane, regulate fluidity
• Cell-to-cell signaling / Adhesion - glycolipids (phospholipids w/ carb chains) and glycoproteins (proteins w/ carb chains)

Mechanism of Transport

• Diffusion - Molecules' tendancy to move from high concentration to low concentration until there's equal distribution...like communism
• Osmosis - Diffusion across semi-permeable membrane
• Facilitated transport (for molecules too big to pass membrane) - use of carrier proteins, still moving from high to low concentration; requires no exertion of energy
• Active transport - still using carrier proteins; molecules "pumped" from low to high concentration; requires exertion of energy
• Membrane transport - movement in/out of cell by using vesicles (small membrane-bound sacks containing molecules); exocytosis - vesicle formed inside cell fuses w/ plasma membrane and releases content outside cell; endocytosis - vesicle formed around outside molecules and is brought inside

Metabolism: Enzymes & Energy

Lawn of Thermodynamics

• Energy cannot be lost, but can be converted from one form to another: potential energy and kenetic energy
• Energy cannot change from one form to another without the loss of useful energy (Hint: heat is not useful energy, since it just floats away and is lost to the environment.)

ATP (Adenosine Triphosphate): contains two high-energy bonds between phosphate groups, give us all energy (all of us...you...me...chimps....whales...strep throat critters...etc...)

We need this crap for:

• Chemical work (building of macromolecules)
• Mechanical work (muscle contraction, nerve impulses)

Friday 9/8/06

Organelles in Eukaryotic cells:

Endoplasmic reticulum (reticulate, adj. = something that's part of and involved in networking)

• both prokaryotic and eukaryotic cells have ribosomes
• but euk.'s have them organized, the rough part has embedded ribosomes and the smooth is involved in synthesizing phospholipids and steiroids

Golgi

• sorts and packages proteins & lipids, which are then ready for secretion

Mitochondria

• most of cell's energy made here
• has a double membrane (outer one is "normal" and inner membrane is squiggly, so it has more surface area to work on - makes sense)
• produces energy through chain reactions - "cell respiration"

carb + oxygen --> "ATP"

Lysosome

• low pH, digestive enzymes
• Down with the foreign antigens; kill them all!

Cilia (hairy-type things) and Flagella (tail) - structures for movement

Week Two


Polar molecules dissolve in water (attraction of partially positive/negative molecules to hydgrogen in the water)

Nonpolar examples: fats, oils

Properties of Water

• High heat capactiy (because of hydrogen bonds), slow changes in temp
• High heat of vaporization (H bonds broken easily)
• Solvent
• Cohesive & Adhesive
• Surface tension
• Less dense when frozen than when fluid (this is how ice floats on liquid water)

pH: indication of solutions' acidity or alkalinity
acidity: high concentration of hydrogen ions (atom w/ a charge)

ex: HCl (hyroclauric acid), in water, becomes: H+ and Cl-

pH 1-6 : acidic (stomach acid: 1)
pH 7 : neutral (water)
pH 8-14: basic (ammonia: 14)

ex: NaOH in water: Na+ and OH- <-- makes solution basic

Organic Molecules: containing both carbon and hydrogen

Carbon is important because: it can form 4 covalent bonds; 2 in first shell, 4 in second, it wants 4
more: very unique

Four classes of Organic Molecules: carbohydrates, lipids, proteins, nucleic acids

Carbs: sugars used as an energy source

monosaccaride: one sugar molecule (in carbs - glucose, simple sugar)
disaccaride: two sugar molecules (such as glucose + fructose = sucrose)
polysaccaride: polymer of monosaccarides

in plants: starch
in animals: glycogen
(long-term storage molecules)

Lipids

Triglycerides: fats & oils; fat molecule is made up of glycerol and 3 fatty acids

unsaturated fats: double H-bonds
saturated fats: H-saturated, pack together well (artery-clogging power of doom)

long-term energy storage: holds more than glycogen & starch

Phospholipid: out of all living cells, phospholipid bi-layer

• Phosphate group ("head"): polar - hydrophillic
• Fatty acids ("tail"): non-polar - hydrophobic

They form a bi-layer which is the plasma membrane around all cells, with hydrophbic fatty acids facing in and hydrophillic phophate groups facing out.

Steiroids: in plasma membrane
Waxes: for protection (plants)

Proteins: polymer made of amino acid monomers

polypeptide: chain of aa's = protein, linked together by polypeptide bond

Structure of Proteins:

• Primary: polypeptide
• Secondary: form alphahelices and beta-pleated sheets
• Tertiary: globular structure
• Quaternary: big messy protein thing

Nucleic Acids: its monomer is a nucleotide

Prymadines (one ring):

• C - cytosine
• T - thymine
• U - uracil

Purines (two rings)

• A - adendine
• G - guanine

DNA (deoxyribonucleic acid): for replication, info to make proteins, shape of a double helix,
a polymer of C, T, A and G
complimentary pairs: C with G
A with T
deoxyribose: sugar in DNA
H bonds in DNA: important for cell replication
DNA contains: sugar, phosphate group, and a base (C, T, A or G)

RNA: ribonucleic acid: involved in protein synthesis, single stranded, base of C, G, A and U

Protein Functions:

• Support (such as keratin in hair & nails; callogen in ligaments & tendons)
• Enzymes (such as amylese for digestion)
• Transport (plasma membrane, channel & carrier proteins)
• Defense (antibodies)
• Hormones (cell-to-cell signalers, such as insulin)
• Motion (such as actin & myosin for muscle contraction)

Cells: smallest unit of living matter, two broad types:

• Prokaryotic: no membrane-bound nucleus
• Uekaryotic: nucleus, membrane-bound

Prokaryotic (bacteria): plasma membrane, cytoplasm (semifluid - contains DNA, enzymes, and
other shit), DNA has one chromosome and is circular
Eukaryotic (protists, fungi, plants, animals): made up of organelles - compartment enclosed by
a membrane with distinct structure & function

Celcius = 5/9 (F-32)
Farenheit: 9/5 C + 32

Week One

Characteristics of life

• organization
• response to environment (stimulus --> response)
• obtain materials and energy
• development/reproduction (sexual or asexual)
• ability to adapt

energy: capacity to do work
metabolism: chemical reaction within cells; need essential molecules obtained from food to
perform these reactions
homeostasis: maintenance of normal internal conditions in a cell/organism by means of
self-regulating (such as body temp, pH balance)
adaptation: genetically determined characteristic that enhances ability of individual to
copy with environment
evolution: descent of organisms from common ancestor with development of genetic and
phenotypic changes over time that make them better-suited to environment
phenotypic: physical manifestation of genetic change
natural selection: mechanism of evolution by environmental selection of organisms most
fit to reproduce; results in adaptation; "form fits function"

Unity & Diversity of Life: united in descent from common ancestor, diversified by different
environments

Levels of Biological Organization

• atom: smallest unit
• molecule: smallest unit of a compound
• cell: smallest unit of a living thing
• tissue: group of cells with common function
• organ: tissues combined for common task
• organ system: organs combined for common task
• organism: an individual
• population: several individuals
• community: interacting populations
• ecosystem: community + environment
• biosphere: Earth

Scientific Method

Observation leads to a Question
Makes an educated guess: a Hypothesis
Experimentation
leads to a Conclusion

A conclusion can turn the experiment right back into more experimentation, or a theory is developed

Scientific Theory: group of ideas that are accepted because of results
Law: theory accepted by many scientists

What an Experiment Needs:

• Experimental variable
• Dependent variable
• Results (organize the data)
• Then a conclusion can be formed: analyzing, determining what's significant, etc.

matter: anything that takes up space
element: substance that cannot be broken down into substances with different properties
molecule: two or more of same element
compound: two or more of different elements

elements' subatomic partices: protons, neutrons, electrons

On the Periodic Table

• protons + neutron = mass number
• protons = atomic number

They want to be electronically stable

Key elements for Bio purposes (these make up 98% of all life):

• C - carbon
• N - nitrogen
• O - oxygen
• P - phosphorus
• S - sulfur
• H - hydrogen

"Organic" = contains carbon

electrons e ` (negative charge): 2 in first shell, as many as 8 in each one after it

octet rule: outermost shell is most stable when it contains exactly 8 electrons;
atoms can give up, accept, or share electrons to fulfill the octet rule
noble gases: stable all by themselves

Chemical Bonds: ionic, covalent, hydrogen bond

Ionic: weak: occurs when electrons are transferred from one atom to another

ex: NaCl (sodium chloride). One electron from outermost shell of sodium (2 +8 +1) transfers to a chlorine atom, which needs one more electron (2 + 8 + 1). Creates a negative ion (Cl) and a positive ion (Na), which attract.

Covalent: very strong, requires energy to break them; occurs when two atoms share electrons

H - H (two hydrogen atoms each sharing an electron with the other)
O = O (two oxygen atoms each sharing two electrons with the other)

Hydrogen: partially negative or positive, creates a polar molecule; very unstable, weak bond;
this is how water is fluid