Biology Module 2 Flashcards
Subatomic Particles
Electron, neutron, proton
Matter
Any material that takes up space
Energy
The ability to move matter ex. heat, light, chemical bonds
Chemical Element
Pure substance that cannot be broken down by chemical means into other substances
Bulk Elements
Needed in large amounts because they make up majority of every living cell
Ex. Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, sodium, magnesium, potassium, calcium.
Trace elements
Required in small amounts
Ex. iron, and zinc
Atom
Composed of three subatomic particles
Protons
Positive Charge
Neutrons
Uncharged
Electrons
Negative Charge
Surround the nucleus
Atomic Number
of protons in the nucleus
Electrically Neutral / no net charge
When # of protons = # of electrons
Ion
An atom (or group of atoms) that gained or lost electrons, and now has net negative or positive charge
Mass Number
Total number of protons and neutrons in its nucleus
All atoms of elements have the same number of protons, but not always same neutrons
Isotope
Different forms of a single element
Atomic Weight
The average mass of all atoms of an element, typically close to mass number of most abundant isotope
Radioactive Isotope
Emit energy as rays of particles when broken down into more stable forms
Half-Life Characteristic
Time it takes for half the atoms in sample to emit radiation or decay to a different more stable form
Molecule
Two or more chemically joined atoms
Compound
Molecule composed of two or more different elements
Orbitals
Describe the most likely location for an electron relative to its nucleus
Energy Cells
Group of electron orbitals that share same attractive force that holds atom together
Atom that lost electrons is an ion carrying positive charge
Atom who gained electron gets negative charge
Ionic Bond
Result from the electrical attraction between two ions with opposite charges
Covalent Bond
Chemical bond were two atoms share electrons, monomer —> polymer
Polar Covalent Bond
Lopsided union in which one nucleus has a stronger pole than the other on the shared electrons (positive + negative ends)
Nonpolar Covalent Bond
Both atoms exerts equal pull on shared electrons
Hydrogen Bond
Weak chemical bond between opposite partial changes on two molecules or within one large molecule
Partial Positive Charge
Is always hydrogen bond
Cohesion
Tendency of water molecules to stick together
Surface Tension
Holds together at its surface
Adhesion
Tendency to form hydrogen bonds with substances other than water
Water is a solvent
A chemical in which other substances called solutes dissolve
Solution
Consist of one or more solutes dissolved in a liquid solvent
Hydrophilic
Attracted to water substances are either polar or charged + dissolve in water
Hydrophobic
Nonpolar molecules that are repelled by water and do not dissolve or form hydrogen bonds with water, resist temperature changes
Evaporation
Liquid —> Vapor (gas)
Water expands upon freezing
Less dense (floats) + molecules are locked
Chemical Reaction
Two or more molecules swap atoms to yield different molecules
Reactant
Starting material in chemical reaction
Product
Result of chemical reaction
Atoms aren’t created or destroyed
They are rearranged and chemical reactions
H+ Ions
Each a hydrogen atom stripped of its electron
Neutral solution
Neither acidic or basic, contains as much H+ as OH-
Acid
Chemical which adds H+ to a solution
Base
Opposite of acid, adds OH- ions, they either come apart to add OH- or absorb H+ ions
Acidic
pH lower than 7, high H+
Alkaline/Basic
pH greater than 7, low H+
pH scale
Each unit represents 10 fold change in H+
Buffers
Weak acid/base pair that resist change in pH
Organic Molecules/Macromolecules
Carbohydrates, Proteins, Lipids, Nucleic Acids. Carbon + hydrogen
Polymers
Long chains of small molecule subunits monomers
Dehydration synthesis/condensation reaction
Chemical reaction used by cells to link monomers into polymers, removes -OH from one molecule and hydrogen atom from another forming H2O
Hydrolysis
Breaks covalent bonds that link monomers enzymes add hydroxyl group to molecule and hydrogen atom to another
Carbohydrates
Organic molecules that consist of carbon hydrogen and oxygen (1:2:1)
Main groups: simple sugars, complex carbohydrates
Monosaccharides
Smallest sugar molecule that contains five or six carbon atoms
Double bond
Share 4 electrons between atoms
Disaccharide
Two bonded monosaccharides joined by dehydration synthesis
Oligosaccharide
Intermediate length carbohydrate consist of 3 to 100 monosaccharides
Glycoprotein
Sugar protein, important for immunity
Polysaccharide
Carbohydrate consists of 100 to 1000 monosacs —> cellulose certain starch glycogen
Protein
Chain of monomers called amino acids (peptide bond)
Amino Acids
Consist of a central atom bonded to a hydrogen atom, a carboxyl group, amino group (-NH2) and R group (side chain)
Organisms use 20
Dehydration synthesis reaction
Connect amino acids to each other
Peptide Bond
Resulting covalent bond that links each amino acid to its neighbor
Two form: dipeptide Three: tripeptide
Polypeptide
100 or more, folds into protein
Primary Structure
Amino acid sequence of a polypeptide chain
Secondary Structure
Localized areas of coils and sheets stabilized by hydrogen bonds
Tertiary Structure
Overall shape of a polypeptide rising, mostly from interactions between R groups and water, abundant in structural proteins
Quarternary Structure
Overall protein shape arising from interactions between multiple polypeptide that make up functional protein
+ only protein with multiple polypeptides have this structure
Protein Shape/Functions
Structural, contraction, transport, storage, enzymes, antibodies
Denature
Changes the shape of protein with heat, excessive salt, or wrong pH
function is destroyed
Nucleic Acid
Long polymer of nucleotides, DNA or RNA
Nucleotides
Building block of nucleic acid, consist of a phosphate group, a 5 carbon sugar, and a nitrogenous base
Nitrogenous Base
Adenine (A), guanine (G), thymine (T), cytosine (C), or uracil (U)
DNA
ATCG: glucose, nitrogen base, phosphate group
two strands of nucleotides entwined to form a double helix shape, held together by hydrogen bonds
RNA
AUCG: single stranded
Lipids
Organic compounds that don’t dissolve in water, consist mostly of carbon and hydrogen
Triglycerides
Consist of three long hydrocarbon chains called fatty acids bonded by glycerol
Glycerol
Three carbon molecule forms, the backbone of triglyceride
Saturated Fatty Acids
Contain all hydrogen possible, a single bond between all carbon atoms
Unsaturated Fatty Acids
At least has one double bond between carbon atom, is oily at room temperature
Steroids
Lipids that have four interconnected carbon rings
Cholesterol
Starting material to make lipids, testosterone and estrogen
Waxes
Fatty acids combined with alcohol or other hydrocarbons, forming a stiff water repellent material
Phospholipids
Form major part of biological membranes (glycerol + Z fatty acids, + phosphate group)
Smallest to largest
Electron, proton, atom
Emulsifer
Molecules with a polar and and a nonpolar, and that can be used to disperse lipids into polar liquids such as water
Valence Shell
Outermost occupied energy shell of an atom, becomes more stable when filled
Phosphodiester Bond
Two hydroxyl groups react with hydroxyl group, backbone of DNA and RNA
Chemotroph
Organism obtain energy from electron in environment ex. bacteria
Orbital
First: 2 Second: 8
Single Water Molecule
Bonds oxygen and hydrogen with covalent bond
One Water Molecule Bonds with another…
Bonds with another water molecule with hygrogen bond
Monomer to polymer
Lose water with dehydration process
Polymer to monomer
Add water molecule
