Biology Test pt 1

• - Organic catalyst, usually a protein, that speeds up a reaction in cells due to it's particular shape
• - Add energy (heat)
• - Not changed or consumed in a reaction, only a small amount is needed & can be reused

• - Reduces the energy needed to reach the activation state
• - Protein enzymes

• - The reactant an enzyme acts on
• - Binding of the substrate causes the enzyme to adjust it's shape slightly, leading to a better induced fit
• - Enzymes have grooves that substrate sit in becoming the active site

• - Store & transmit hereditary information
• - Deoxyribonucleic acid (DNA)
• - Ribonucleic acid (RNA)
• - Polymers called Polynucleotides
• - Monomers called Nucleotides
• - Each nucleotide consist of a nitrogenous base, a pentose sugar, & a phosphate group

• - Direct synthesis of messenger RNA (mRNA) & through mRNA control protein synthesis
• - Provides directions for it's own replication
• - DNA molecule has 2 polynucleotides sprialing around an imaginary axis, forming a double helix
• - The 2 backbones run in opposite 5' to 3' directions
• - Form hydrogen bond 'A pairs with T' & 'G pairs with C'

• - Primary energy-transferring molecule in the cell
• - "Energy Currency"
• - Consists of an organic molecule - adenosine attached to a string of 3 phosphate groups
• - Energy is released from ATP when bond is broken
• 

• Protein Functions
• - Structural support/Storage/Movement
• - Messengers
• - Transport
• - Defense
• - Catalysis
• Composed of one or more polypeptides
• Shape of protein determines it's function

• Monomers of polypetides/protiens
• - Composed of a carboxy group, amino group, & an "r" group
• - "R" group makes the properties of the amino acid different
• - Cells use 20 amino acids to amke thousands of proteins
• (will give up a hydrogen making it COO-)

• -Polymer of amino acids, joined by a peptide bond to from a long chain
• - Unique linear sequence of amino acids

• 1. Primary structure: unique sequence of amino acids
• 2. Secondary structure: consists of coils & folds in the polypeptide chain
• 3. Tertiary structure: determined by interactions among various side chains ("R" group)
• 4. Quaternary structure: Results when a protein consist of multiple polypeptides

• - Loss of normal shape by an enzyme so that it no longer functions
• - Alternation in pH, Salt concentration, temp & other enviornmental factors
• - Denature protein is biologically inactive

• - Compound that is insoluble in water
• - Utilized for energy storage, membranes, insulation, & protection
• - Hydrophobic

• - Constructed from 2 types of smaller molecles: glycerol & fatty acids
• - Major function of fats is energy storage
• - Saturated fats: saturated fatty acid, mostly animal fat, solid at room temp
• - Unsaturated fats: unsaturated fatty acid, plants & fish fats, liquid at room temp (double bonded, causes bending)

• - molecule that form the bilayer of the cell's membranes
• - 2 fatty acids attached to glycerol & a phospate group
• - Polar head (hydrophilic)
• - Nonpolar tails (hydrophobic)
• - Assemble so that the polar heads are pointing outward & the nonpolar tails are pointing inward
• 

• - 3 fatty acids are joined to a glycerol by an ester linkage
• - Energy storage

• - Lipids characterized by a carbon skeleton consisting of 4 fused rings
• - Cholesterol: important steroid, component in animal cell membranes, precursor from which all other steriods are synthesized
• - Testosterone & Estrogen
• - Nonpolar: can go through cell membranes
• 

• - Serve as energy & building material
• - Include sugar & polymer of sugar

• - Simplest carbohydrate/single (simple) sugars
• - Used for short term energy storage, serve as structural componets of larger organic molecules, & source of carbon
• - Classified by location of carbonyl group & by # of carbons in the carbon skeleton

• - Formed when a dehydration reaction joins 2 monosaccharide
• - This bond is called a glycosidic linkage
• - Lactose, Maltose, Sucrose (common table sugar)

• - Complex carbohydrate, polymer of monosaccharides (long chains of simple sugar)
• - Storage & structral roles
• - Starch (storage polysaccharide of plants)
• - Glycogen (storage polysaccharide of animals)
• - Cellulose (component of the tough wall of plant cells)

• - Repeated units are small molecules (building blocks)
• - Connected by Covalent bonds that form through the loss of a water molecule
• Monosaccharide
• Glycerol & Fatty acid
• Amino Acid
• Nucleotide

• - A long molecule consisting of many similar or identical building blocks linked by covalent bonds
• - Built from monomers
• Polysaccharide (carbohydrates)
• Lipid
• Protein
• Nucleic Acid

• - Unique in it's ability to form large, complex, & dicerse molecules
• - Carbon compounds since it only needs 4 electrons it can make single, double, or triple bonds
• - Can form long chains or rings
• - Carbon chains form the skeleton of most organic molecules

• - Groups of atoms that are attached to the skeleton of organic molecules
• Hydroxyl Group: Carbohydrate, Alcohols
• Carbonyl Group: Formaldehyde
• Carboxyl Group: Amino Acids, Vinegar
• Amino Group: Ammonia
• Sulfhydryl Group: Proteins, Rubber
• Phosphate Group: Phospholipids, Nucleic Acids, ATP
• 

• - Splitting of a compound by the addition of water, with the H+ being incorporated in one fragment and the OH- in the other
• - Bonds are broken by adding water molecules

• - Chemical reaction resulting in a covalent bond with the accompanying loss of a water molecule
• - Remove a water molecule, forming a new bond

- Compounds with the same molecular formula but different structural formulas

• - Particle that carries a negative or positive charge
• Anion: negative
• Cation: Positive

- Smallest particle of an element that displays the properties of the element

- Substance that cannot be broken down into substances with different properties; composed of only one type of atom

• - Scientific study of life
• - Multidisciplinary science drawing on the insight from other sciences

• Mass= Grams: g
• Lengeth= Meter: m
• Volume= Liter: l

• tera (T) 1 trillion 10^12
• giga (G) 1 billion 10^9
• mega (M) 1 million 10^6
• kilo (k) 1 thousand 10^3
• hecto (h) 1 hundred 10^2
• deka (da) 1 ten 10
• Base Unit (m,g,l)
• deci (d) 1 tenth 10^-1
• centi (c) 1 hundredth 10^-2
• milli (m) 1 thousandth 10^-3
• micro (µ) 1 millionth 10^-6
• nano (n) 1 billionth 10^-9
• pico (p) 1 trillionth 10^-12

- maintenance of normal internal conditions in a cell or an organism by means of self-regulating mechanisms

• - Form high degree of ordered structures
• - Regulate internal conditions
• - Harvest and use energy
• - Reproduce and evolve
• - Grow and develop
• - Respond to environmental stimuli

• Organ systems
• Organ
• Tissues
• Cells
• Organelles
• Molecules
• Atom

Mechanism of evolution caused by environmental selection of organisms most fit to reproduce; results in adaptation of the enviornment

• - Proton: positive subatomic particle, located in the nucleus
• - Neutron: neutral subatomic particle, located in the nucleus
• - Electrons: negative subatomic particle, that has no weight, orbits the nucleus of an atom in an orbital
• 

- Atom of the same element having the same atomic number but a different mass number due to the number of neutron

- Union of 2 or more atoms of the same element; also the smallest part of a compound that retains the properties of the compound

- Enable atoms to give up or acquire electrons in order to complete their outer shell

• - Anything that takes up space & has mass
• solid
• liquid
• gas

• - Chemical bond in which atoms share one pair of electrons
• 

• - Chemical bond in which ions are attracted to one another by opposite charges
• 

• - One atom is more electronegative & the atom do not share the electron equally
• 

• - The atoms share the electron equally
• 

• - Forms when a hydrogen atom already bonded is attracted to another electronegative atom
• 

- General process in which ionic compounds separate or split into smaller particles

• - Cohesion: molecules attract other water molecules
• - Capillarity: water molecules climb
• - Adhesion: water molecules attract other chraged substances
• - High heat of vaporization
• - Solvent
• - High heat capacity: resist changes in temp

• (water loving) Dominated by ionic or polar bonds
• can absorb water

• (water fearing) Noniconic & have nonpolar covalent bond
• major molecules of cell membranes

• Number of molecules in a unit
• Avogadro's number 6.02x10^23

• - Substance or group of substances that tend to resist pH changes in a solution
• - Important to living organism
• - Accept hydrogen ion from the solution when they are in excess and donate hydrogen ion when they have been depleted

• - Molecules tending to lower the hydrogen ion concentration in a solution and raise the pH numericaly
• pH 14 -> 8

• Molecules tending to raise they hydrogen ion concentration in a solution and to lower it's pH numerically
• pH 6 -> 1

• Simplest organism
• 

• - Characterized by compartmentalization by an endomembrane system & the presence of membrane-bound organelles
• - Type of cell that has a membrane-bound nucleus & organelles
• 

• - Model of the plasma membrane based on the changing location & pattern of protein molecules in a fluid phospholipid bilayer
• 

• - Contents of a cell between the nucleus & the plasma membrane that contain the organelles
• - Semi-fluid material (nucleoplasm & cytosol)

• - Interstitial fluid: fluid on the exterior of the cell within tissues
• - Plasma: fluid component of blood

• - Homogeneous mixture of 2 or more components
• Solvent: dissolving medium
• Solutes: components in smaller quantities within a solution

• - Movement of molecules or ions from a region of higer concentration to one of lower concntration; it requires no energy & stops when the distribution is equal
• - Movement is random
• 

• - Random movement of the molecules will cause some to pass through the pores trying to reach equilibrium
• - Higher concentration will diffuse first
• so there is a different rate of diffusion depending concentration

• - Composed of a lipid bilayer w/ globular proteins embedded in the bilayer
• - Membrane surrounding the cytoplasm that consist of a phospholipid bilayer w/ embedded protein
• - Regulates the entrance & exit of molecules from the cell
• - It's a boundry & protects
• Keeps things in & out
• 

• Transport
• Enzymatic activity
• Signal transduction
• Cell-cell recognition
• Intercellular joining
• Attachement to the cytoskeleton & extracellular maxtrix
• 

• - Selective permeability, it allows some substances to cross it more easily than others
• - Passive transport : simple diffusion, dialysis, osmosis, facilitated diffusion
• - Active transport: membrane pump, coupled transport
• 

• Factors: lipid solubility, size, charge (electronegativity), presence of channels & transporters
• - Hydrophobic molecules are lipds soluble & can pass through the membrane rapidly
• - Polar molecules do not cross rapidly
• - Transport protein allow passage of hydrophilic substance across the membrane