ch. 4 Flashcards
98% of the mass of living organisms consists of just six elements:
The most abundant compound in cells is ?
hydrogen, oxygen, nitrogen, phosphorus, sulfur, carbon
water
name the 4 organic macromolecules:
lipids, nucleic acids, proteins, carbs
an ? consists of a ? charged nucleus that contains protons and neutrons surrounded by ? charged electrons; they make up molecules
atom, +, -
an ? is the type of atom; it is a substance composed entirely of one specific type of atom
element
the atomic number identifies the number of ?, which is the property that defines an element
protons
the ? number = sum of protons & neutrons
mass
the ? ? average mass number of the isotopes of an atom
atomic weight
? are versions of the same element that have the same number of protons but different numbers of ? in their nuclei.
isotopes, neutrons
?-? is the time it takes for half of a radioactive substance to decay into a different substance
Half-life
? are regions around an atom’s nucleus where electrons are most likely to be found
orbitals
Atoms that share electrons form a ?
molecule
The sharing of ? between two atoms is called a covalent bond
electrons
A molecular formula is a shorthand notation indicating the ? and ? of atoms present in a ?.
number, type, molecule
A ? formula is a way of representing a molecule that shows how the atoms are arranged and ? to each other.
ex. H-O-H > gives water the name H₂O.
structural, bonded
? are atoms or molecules that have gained or lost electrons, giving them an ? charge; charged particles
positive ions:
negative ions:
ions, electric, cations, anions
? are charged particles (ions) that help conduct electricity in the body. They are vital for ?, nerve signals, and ? function.
electrolytes, hydration, muscle
a bond or charge attraction between anions and cations is called an ? ?
ionic bond
? bonds occur when two atoms share electrons equally
? bonds happen when electrons are shared unevenly, resulting in a partial positive charge on one atom and a partial negative charge on the other.
nonpolar, polar
a ? bond is the weak partial attraction between the hydrogen atom of one water molecule and the ? atom of another water molecule, where the hydrogen has a slightly ? charge and the oxygen has a slightly ? charge, creating an ? attraction between them.
hydrogen, oxygen, +, -, electrostatic
hydrophilic
hydrophobic
water loving
water fearing
Cells are largely made of ? molecules, defined as molecules that contain a ?-carbon bond.
organic, carbon
a large organic molecule is considered a
macromolecule
A ? group is a specific group of ? in a molecule that gives the molecule its characteristic bonding, ?, properties, and reactivity.
functional, atoms, shape
? are organic molecules that serve as ? components of membranes and other parts of cells. Lipids store lots of ? (as in “calories”) because their large number of C–H bonds release energy when metabolized with the ? we breathe
lipids, structural, energy, oxygen
? fats have ? double bonds between carbon atoms, meaning they are “saturated” with hydrogen atoms, and are typically ? at room temperature
saturated, no, solid
? fats have ? double bonds between carbon atoms, which creates kinks in the chain, and are usually ? at room temperature
unsaturated, 1+, liquid
A ? reaction is a chemical reaction where two molecules ? to form a larger molecule, releasing a small molecule, like water, as a byproduct.
condensation, combine
? are organic compounds made of ?, ?, and ?, and they are a primary source of ? for the body. They include sugars, starches, and fibers.
carbohydrates, C.H.O, energy
A ? is the simplest form of ?, consisting of a single sugar molecule, such as glucose, fructose, or galactose. It serves as a basic building block for larger carbohydrates.
monosaccharide, carbs
A carbohydrate composed of 2 simple sugars joined by a covalent bond is called a ?
disaccharide
A ? (or glycan) is a complex carbohydrate made up of many monosaccharide units linked together; a carbohydrate ? composed of ? sugars.
polysaccharide, polymer, simple
The complete genetic content of an organism is called the
genome
A ? is the basic building block of ? ? (DNA and RNA), consisting of a 5-carbon-sugar, a phosphate group, and a nitrogenous base (A,T,G,C,U); the ? unit of nucleic acids
nucleotide, nucleic acids, monomer
A ? is a nitrogenous base that pairs with other bases to form the structure of DNA or RNA.
nucleobase
a ? is a macromolecule made of multiple ? subunits that work in a coordinated manner
complex, protein
An ? ? is a building block of proteins, consisting of a central carbon atom bonded to an ? group, a ? group, a ? atom, and a variable side chain (R group) that determines its properties.
amino acid, amino, carboxyl, hydrogen
? are molecules that have the same chemical formula but different structures or arrangements of atoms
isomers
When discussing protein structure, “primary” refers to the ? ? sequence, “secondary” to local ? patterns like alpha helices, “tertiary” to the overall ? ? of a ? polypeptide chain, and “quaternary” to the ? of ? polypeptide chains within a protein complex.
amino acid, folding, 3D shape, single, arrangement, multiple
The fully folded, functional form of a protein refers to ? ?
native conformation
? means to greatly increase the rate of a reaction.
catalysis
? ? ? is the difference in free energy between the reactants and products of a reaction. this change reflects the energy available to do work during a ? process.
free energy change, chemical
? is the ability to do work.
energy
First Law of Thermodynamics: Energy cannot be ? or ?, only ? or ?. The total energy in a system remains ?.
created, destroyed, transferred, transformed, constant
Second Law of thermodynamics:
In every transfer or transformation of energy, some energy is lost, and as a result, the ? of the system will ?.
entropy means ? or randomness in a system
entropy, increase, disorder
?: Reactions that release energy, with a negative free energy change. These reactions are ?.
exergonic, spontaneous
?: Reactions that require energy input, with a positive free energy change. These reactions are ?.
endergonic, non-spontaneous
Molarity is the measure of the ? of a ?, expressed as the number of ? of solute per liter of solution
concentration, solution, moles
The energy needed for reactants to reach the transition state between reactants and products is called ? ?.
activation energy
an ? biological catalyst; a protein or RNA molecule that can speed up the rate of a reaction without itself ? ?.
enzyme, being changed
if a bacterium’s enzyme becomes denatured, this means that the enzyme
loses its structure
“LEO the lion says GER.”
reduction is the ? ? ?
oxidation is the ? ? ?
gain of electrons, loss of electrons
The ? agent causes another substance to be oxidized. (gain)
The ? agent causes another substance to be reduced. (loss)
oxidizing, reducing
the ? ? is the phospholipid bilayer that encloses the ? which contains aqueous fluid.
cell membrane, cytoplasm
? are a type of lipid molecule made up of a glycerol, two fatty acid tails (hydrophobic), and a ? group with a polar head (hydrophilic). They are the main components of cell membranes, forming a bilayer that separates the cell’s interior from its ?.
phospholipids, phosphate, environment
The phospholipid bilayer is a double layer of phospholipids that makes up the core structure of ? membranes.
The ? tails (fatty acids) face inward, avoiding water.
The ? heads (phosphate groups) face outward, interacting with water. This arrangement creates a flexible, semi-permeable barrier that regulates the ? of substances in and out of the cell.
cell, hydrophobic, hydrophilic, movement
? proteins span (overlap) across the entire membrane, with parts exposed on both the inside and outside of the cell. They often function as channels or ? for molecules to pass through the membrane.
transmembrane, receptors
? membrane proteins are attached to the outer or inner surface of the membrane, not embedded in it or overlapping. They help with cell ?, cell recognition, or maintaining the cell’s shape.
peripheral, signaling
Weak acids (e.g., aspirin) tend to be ? in ? environments (low pH), which allows them to cross cell membranes. In more ? environments (higher pH), they dissociate into a ? (H⁺) and a conjugate base, becoming charged and less likely to cross the membrane.
Weak ? (e.g., nicotine) tend to be uncharged in ? environments (high pH), allowing them to pass through membranes. In ? environments (low pH), they can accept a proton (H⁺) and become charged, which prevents them from easily ? the membrane.
uncharged, acidic, basic, proton
bases, basic, acidic, crossing
? is the net movement of molecules from an area of high concentration to one of low concentration.
? is the diffusion of water across a selectively permeable membrane from regions of high water concentration (low solute) to regions of low water concentration (high solute).
diffusion, osmosis
?: A solution where the concentration of solutes is the same inside and outside the cell, causing no net movement of water.
?: A solution with a higher concentration of solutes outside the cell, causing water to move out and the cell to shrink.
?: A solution with a lower concentration of solutes outside the cell, causing water to move in and the cell to swell.
isotonic, hypertonic, hypotonic or isosmotic, hyperosmotic, hypoosmotic
?—a rupturing of the cell membrane and dispersal of cell contents. The sudden increase of osmotic pressure is called ? ?
lysis, osmotic shock
? are specialized structures within a cell that perform specific functions.
a hollow sphere is called a ?
? is the invagination of the cell membrane to form a vesicle that contains extracellular material
An ? is a membrane-bound compartment within a cell that forms during the process of endocytosis
organelles, vesicle, endocytosis, endosome
? are temporary extensions of the cell membrane used for movement or engulfing substances.
? is the process by which a cell engulfs and digests foreign particles or microorganisms.
? is the vesicle formed when a cell engulfs a particle during phagocytosis.
? are membrane-bound organelles in cells that contain digestive enzymes, responsible for breaking down ?, damaged organelles, and foreign substances. they are not found in ? cells.
pseudopods, phagocytosis, phagosome, lysosomes, waste, plant
Reaction rates are affected by ? and ?.
temp, pH
