Key Terms_ Chapter 1 to 8

Chapter 1 :

biology = ongoing inquiry about the nature of life

evolution = the process of change that has transformed life on Earth from its earliest beginnings to the diversity of organisms living today

reductionism = the reduction of complex systems to simpler components that are more managable to study

cell = organism's basic units of structure and function

system = a simply combination of components that function together

gene = a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA/RNA (in some viruses)

DNA = deoxyribonucleic acid

genome = the entire "library" of genetic instructions that an organism inherits

inquiry = a search for information and explanation

hypothesis = tentative answer to a well framed question

Chapter 2 :

matter = anything that takes up space and has a mass

element = substance that cannot be broken down to any other substance by any chemical reactions

compound = substance consisting in two or more different elements combined in a fixed ratio

atom = the smallest unit of matter that still retains the properties of an element

dalton = atomic mass unit

atomic number = number of protons, subscript to the left of the symbol

mass number = sum of the protons and neutrons in the nucleus of an atom, superscript to the left of the symbol

energy = capacity to cause change, especially to do work

orbital = 3D space where electron is found 90% of the time

valence = bonding capacity, usually equals to number of unpaired electrons

Chapter 3 :

polar molecule = molecule whose two ends have opposite charges

cohesion = the binding together of like molecules, often by hydrogen bond

adhesion = the clinging of one substance to another

kinetic energy = energy of motion

heat = form of energy

temperature = a measure of heat intensity (average kinetic energy of the molecules)

vaporization (evaporation) = transformation from liquid to gas

heat of vaporization = the quantity of heat a liquid must absorb for 1 g to be converted from the liquid to the gaseous state

solution = a liquid that is completely homogeneous mixture of two or more substances

solvent = dissolving agent of a solution

solute = substance that is dissolved

acid = a substance that increases the hydrogen ion concentration of a solution

base = a substance that reduces the hydrogen ion concentration of a solution

Chapter 4 :

Organic Chemistry = branch of chemistry that specializes in the study of carbon compounds

Vitalism = the belief in a life force outside the jurisdiction of physical and chemical laws

Mechanism = the view that physical and chemical laws govern all natural phenomena, including the process of life

Tetravalence = ability of the molecule to branch off in as many as four directions

Hydrocarbons = Organic molecules made of only carbon and hydrogen

Isomers = Compounds with the same molecular formula but have different structures

Enantiomers = molecules that are mirror images of each other.

Functional groups = A group of atoms attached to a carbon skeleton

ATP = adenosine triphosphate, an important source of energy

ADP = adenosine diphosphate, product of losing one phosphate from ATP

Chapter 5 :

Macromolecules (polymers) = Large molecules formed by joining many subunits together

Polymer = molecule that consists of a single unit (monomer) repeated many times

Monomer = A building block of a polymer

Dehydration/ Condensation synthesis = the chemical reaction that joins monomers into polymers. Covalent bonds are formed by the removal of a water molecule between the monomers

Hydrolisis = Reverse of

condensation synthesis. Breaks polymers into monomers by adding water.

Polypeptide = polymers of amino acids

Proteins = polypeptide chains of Amino Acids linked by peptide bonds

Fatty acid = a long carbon chain (12-18 C) with a -COOH (acid) on one end and a -CH₃ (fat) at the other.

Denaturation = pH shifts, high salt concentrations, heat

Nucleotide = monomer

Chapter 6 :

cell = basic functional unit of all living things

lipid bilayer = double phospholipid membrane --> outer hydrophilic heads and hydrophobic tails pointing towards inside

organelles = bodies within the cytoplasm that serve to physically separate the various metabolic reactions that occur within the cells

nucleus = brain of the cell

ribosome = consisting of RNA

endoplasmic reticulum = stacks of flattened sacs involved in the production of various materials

golgi apparatus = group of flattened sacs arranged like a stack of bowls, functioning to modify and package proteins and lipids into vesicles

lyzosomes = vesicles from a golgi apparatus that contain digestive enzymes

mitochondria = organelles that carry out aerobic respiration

chloroplasts = organelles that carry out photosynthesis

flagella and cilia = structures that protrude from the cell membrane and make wavelike movements

Chapter 7 :

Integral proteins = transmembrane protein with hydrophobic regions that extend into and often completely span the hydrophobic interior of the membrane and with hydrophilic regions in contact with the aqueous solution on either side of the membrane

Peripheral proteins = proteins loosely bounded to the surface of a membrane or to part of an integral protein and not embedded in the lipid bilayer

Glycolipids = molecules formed of membrane carbohydrates covalently bonded to lipids

Glycoproteins = membrane carbohydrates + proteins

Aquaporins = channel proteins (facilitate the passage of water molecules through the membrane)

Diffusion = the movement of molecules of any substance so they spread out evenly into the available space (passive transport)

Osmosis = the diffusion of water

Facilitated diffusion = the spontaneous passage of molecules or ions across a membrane with the assistance of specific transmembrane transport proteins

Passive transport = no energy required / invested

Active transport = energy required

Chapter 8 :

Metabolism = the totality of an organism’s chemical reactions

Energy = the ability to do work

Kinetic energy = energy of motion / action

Potential energy = tored energy or capacity to do work

Energy of activation = Energy needed to convert potential energy into kinetic energy

Entropy = measure of disorder

Free energy = portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell

Exergonic reaction = release of free energy

Endergonic reaction = absorbs free energy

Energy coupling = a key feature in the way cells manage their energy resources to do work (chemical, transport, mechanical)

Phosphorylated = the recipient of the phosphate group