SCI 230: Exam 1

• Verifiable observations and measurements
• Describe life in variety of ways
• "Descriptive science"

• Series of steps
• Observations, hypothesis, experiment, result

• A testable statement
• "If __ occurs, then __ will result."
• Has to be able to be proven false

• Binomial nomenclature
• Genus = capital letter
• species = lowercase letter

• Domain Bacteria
• Domain Archaea
• Domain Eukarya

• Plant
• Fungi
• Animal
• Protist

• Living organisms:
• 1) Reproduce
• 2) Grow and develop
• 3) Process energy
• 4) Regulation
• 5) Interact
• 6) Order
• 7) Evolutionary Adaptation

An observation that has been repeated confirmed and for all practical purposes is accepted as true.

• A descriptive generalization about how some aspect of the natural world behaves under stated circumstances
• 1st Law of Thermodynamics

• A well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypothesis.
• Theory of Evolution
• Evidence behind it

• The body of knowledge grows and science adapts to this new knowledge
• Science can change (planets)
• Body of science tends to be self-correcting

An apparent statistical relationship between variables

Established relationship between variables

• In nucleus
• 1 unit of positive charge

• Revolve around nucleus
• 1 unit of negative charge

• In nucleus
• 0 charge

• Center of atom
• Made up of protons and neutrons

• The number of electrons in the outermost shell determines how the atom reacts
• with other atoms and molecules
• If the outermost shell is incomplete, then the atom or molecule is reactive

Have the same number of protons and electrons, but different number of neutrons

Determined by number of protons

Are ionic compounds that are held together by the attraction of opposite charge

Atoms/molecules with a + or – charge

Share electrons

• Form between water molecules as they align themselves by opposite charges (H +, O -)
• They stay bonded for only a short time

• Each pH unit represents a 10-fold change in concentration
• pH 7 = Neutral
• pH 2 = Acidic
• pH 8 = Base

• Chemicals that releases H+ to a solution (increase the concentration (relative number) of H+ ions)
• The more H+ ions, the stronger the acid

• Chemical bond that accepts H+ ions and removes it from a solution (leaving behind OH- ions)
• The more OH- ions, the stronger the base

• Oxygen, Carbon, Hydrogen, and Nitrogen
• Phosphorous

• Water
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids

• Some are radioactive = Nucleus decays, giving off particles and energy
• Higher isotopes, more dangerous

• Similarities = Both have complete outer shells and positive and negative charges hold them together
• Differences = I bonds gain and lose electrons, but C bonds don't / I bonds form ionic compounds, but C bonds form molecules

• Less than 3%
• Only about 0.5%

• Covalent bond
• The oxygen atom pulls all the electrons (water = 10e-) much more strongly to them than the hydrogen atoms, so they don’t share the electrons equally.
• Electrons are mostly on the oxygen, so it shifts to the negative pole

• Hydrogen bonds take place between water molecules by opposite charges
• Ionic = Stronger charge
• Covalent = Share electrons

• Liquid water is cohesive - H bonds cause water molecules to stick together and pull each other up (Surface tension, moving water in trees)
• Ice is less dense than liquid water - Water molecules are spread apart, so there are less water molecules in a large space.
• Water moderates temperature - Water heats up and cools down slowly. (Evaporative cooling - sweating, Coastal Areas)
• Water is the universal solvent - Many things dissolve in water (H bonds pull Na and Cl into water.)

Most dense at 4C (39.2F)

The acidity or alkalinity of a solution on a scale in which 7 is neutral, lower values are more acidic and higher values are more basic.

• It represents a tenfold change in concentration.
• Lemon juice (pH-2) is 10 times more acidic than grapefruit juice (pH-3)
• Multiply by 10 for each

pH 6.5 - 8.2

Rain, snow, or fog has a pH below 5.6.

Caused by sulfur and nitrogen oxides, mostly from burning fossil fuels.

• Most simple carbon molecules
• Hydrogen and carbon only4 bonds for each carbon

Subunits of polymers

Molecules built by linking together a large number of subunits

• “To form by removing water”
• -OH and –H are removed
• Making water H2O

• Monomers are broken off of polymers using a process
• Water is added to break the polymer
• Split into –OH and –H

• Monosaccharides
• Disaccharides
• Polysaccharides

• "Water loving"
• Hydrogen bonds form between oxygen atoms on water or carbohydrate molecules and hydrogen atoms on the other
• Large molecules attract water, small molecules dissolve in water

• "Fear of water"
• Molecules are repelled from water

Triglyceride

• 3 fatty acids chains linked to glycerol
• Main function = Energy storage

20 Amino Acids monomers

• Structural – Hair, tendons, silk (spiders)
• Contractile – Provide movement (muscles)
• Signaling – Messages within cells and from one cell to another
• Enzymes – Greatly increase the rate of reactions in cells

• Information storage in cells
• Made up of carbon, oxygen, hydrogen,
• nitrogen, and phosphorus

Monomers

There are 5 nitrogenous bases in proteins

• Carbohydrates - Energy and structure
• Lipids - Energy and structure
• Proteins - Structure, enzymes, and signaling
• Nucleic Acids - Storage of genetic information

• Large amount of energy is stored in the Carbon-Hydrogen bonds
• This is where most of the energy is stored in macromolecules

• Carbohydrates are made up of carbon (c),
• hydrogen (H), and oxygen (O) and hydrocarbons which are hydrogen and carbon only
• Carbohydrates are our primary source of energy and hydrocarbons is where energy is stored, but can't use the energy

• Polymers are built from monomers through
• the process of dehydration synthesis.
•  - “To form by removing water”
•  - Making water H2O
• Monomers are broken off of polymers using a process called hydrolysis
•  - Water is added to break the polymer

Hydrocarbons store the most energy

• Glucose
• Fructose
• Galatose

• Sucrose = Table sugar
• Maltose = Beer
• Lactose = Milk sugar

• Starch - Storage in plant roots and seeds, found in food (potatoes)
• Glycogen - Stored in muscle cells for quick energy
• Celluose - Plant cell walls, wood

• C=O group plus a hyrdocarbon chain (about 15-18 carbons long)
• 3 fatty acids chains linked to glycerol - triglycerides (another name for fat)

• Saturated - Fatty acids filled with the maximum number of hydrogen atoms on the carbon chain
• Unsaturated - Fatty acid with less than the maximum number of hydrogen atoms on the carbon chain

• Solid - Packed tightly because they are straight lined (saturated)
• Liquid - Can't pack tightly because they are bent (unsaturated)

• Unsaturated fats that have been partially hydrogenated (H atoms added)
• Adding H atoms often makes double bonds
• in the trans configuration (across the bond)
• Nutrition labels lie about having trans fats or “partially hydrogenated oils or hydrogenated oils.”

• Primary Structure -Unique sequence of amino acids / Different sequence for each protein
• Secondary Structure - Interactions caused by hydrogen bonds
• Tertiary Structure - Proteins automatically go into its 3D shape as they are being formed in water

• Hydrogen bonds
• Hydrophobic / hydrophilic interactions
• Hydrophobic = Inside protein (get away from water), Hydrophilic = Outside protein (attract water)

3-D shape determines the function of the proteins

• Sugar
• Phosphate Group
• Nitrogenous Base

Sugar and phosphate groups

Sugar and phosphate groups