BIO 2401: Chapter 2

Glycolysis

"Sugar splitting." Splits the six-carbon glucose molecule into two three-carbon molecules of pyruvic acid.

Deoxyrobonucleic acid (DNA)

100 million to 1 billion nucleotides long. Constitutes our genes, gives instructions for synthesizes all of the body's proteins, and transfers hereditary information from cell to cell when cells divide and from generation to generation when organisms reproduce.

solution (sodium chloride) solute solvent

A ____ consists of particles of matter called the ____ mixed with a more abundant substance (usually water) called the ____

amino acid

A ____ has a central carbon atom with an amino (-NH2), carboxyl (-COOH), and R group

peptide peptide bonds

A ____ is any molecule composed of two or more amino acids joined by ____

Triglyceride (also called neutral fats) glycerol

A _____ is a molecule consisting of a three-carbon alcohol called _____ linked to three fatty acids. Liquid at room temperature

Metabolic pathway

A chain of reactions with each step usually catalyzed by a different enzyme.

Fatty acid

A chain of usually 4 to 24 carbon atoms with a carboxyl group at one end and a methyl group at the other. Can be either saturated or unsaturated.

Reduction

A chemical reaction in which a molecule gains elections and energy.

Reversible reactions

A chemical reaction that results in an equilibrium mixture of reactants and products. aA + bB <--> cC + dD

Buffer

A chemical solution that resists change

Antioxidant

A chemical that neutralizes free radicals.

Secondary structure alpha helix beta sheet (pleated sheet)

A coiled or folded shape held together by hydrogen bonds is the ____. Most common shapes:

Carbohydrate

A hydrophilic organic molecule with the general formula (CH2O)n

Lipid

A hydrophobic organic molecule, usually composed only of carbon, hydrogen, and oxygen, with a high ratio of hydrogen to oxygen.

Decomposition reaction

A large molecule breaks down into two or more smaller ones. AB --> A + B

Chemical bond

A molecule is held together, and molecules are attracted to one another, by forces called ___

Denaturation

A more drastic conformational change in response to conditions such as extreme heat or pH.

Aerobic respiration

A more efficient pathway when oxygen is available. Break pyruvic acid down to carbon dioxide and water and generates more ATP. Reactions are carried out in mitochondria.

Cyclic adenosine monophosphate (cAMP)

A nucleotide formed by the removal of both the second and third phosphate groups from ATP. Acts as a "second messenger" to activate metabolic affects within the cell.

Chemical reaction

A process in which a covalent or ionic bond is formed or broken.

polymer

A protein is a ____ of amino acids

Base

A proton acceptor - accepts H+ ions in water.

Acid

A proton donor - releases H+ ions in water.

Cellulose

A structural polysaccharide that gives strength to the cell walls of plants.

Emulsion

A suspension of one liquid in another.

Hydrolysis

A water molecule ionizes into OH- and H+.

<7.0 (H+>OH-)

Acidic pH

pH

Acidity is expressed in terms of ____, a measure derived from the molarity of H+.

Metabolism

All the chemical reactions in the body are called

-NH2 Amino acids, proteins

Amino functional group

Eicosanoids

An arachidonic acid that functions as a hormone-like chemical signal between cells.

Glycogen

An energy-storage polysaccharide made by cells of the liver, muscles, brain, uterus, and vagina.

Enzyme-substrate specificity

An enzyme will catalyze only one particular reaction.

Cofactor

An inorganic substance (other than the substrate) whose presence is essential for the activity of an enzyme.

Coenzyme

An organic compound that is necessary for the functioning of an enzyme.

saturated fats polyunsaturated fats

Animals fats are usually made from ____ and are solid at room temperature. Most plant triglycerides are ____ which generally remain liquid at room temperature.

Oxidation

Any chemical reaction in which a molecule gives up electrons and releases energy.

Ligand

Any hormone or other molecule that reversibly binds to a protein

>7.0 (OH->H+)

Basic pH

Democritus

Called imaginary particles atoms (indivisible)

Conjugated

Carbohydrates are often ___ with (convalenty bound to) proteins and lipids.

Unsaturated fatty acid

Carbon atoms are joined by double covalent bonds.

-COOH Amino acids, sugars, proteins

Carboxyl functional group

oligopeptides polypeptides

Chains of fewer than 10 or 15 amino acids are called ____ and chains larger than that are called ____

Ion

Charged particle with unequal number of protons and electrons.

Steroid hormones

Chemical messenger between cells

Molecules

Chemical particles composed of two or more atoms united by a chemical bond.

Free radicals

Chemical particles with an odd number of electrons. Cause tissue damage.

Marie Curie

Coined the term radioactivity. First woman to receive a Nobel Prize and first women in France to receive a PhD.

Cholesterol

Component of cell membranes; precursor of other steroids.

Glycoprotein

Component of the cell surface coat and mucus.

Glycolipid

Component of the cell surface coat.

Prosthetic group

Conjugated proteins have a non-amino acid moiety called a ____ covalently bound to them.

Catabolism

Consists of energy-releasing decomposition reactions.

Anabolism

Consists of energy-storing synthesis reactions.

Mixture

Consists of substances that are physically blended but not chemically combined.

Nonpolar covalent bond

Covalent bond in which electrons are equally attracted to both nuclei. Strongest type of chemical bond.

Polar covalent bond

Covlaent bond in which electrons are more attracted to one nucleus than to the other resulting in slightly positive and negative regions in one molecule.

Electrons

Determine the chemicals properties of an atom. Governs what molecules can exist and what chemical reactions can occur.

John Dalton

Developed atomic theory. Believed every atom of an element was identical.

Physical half-life

Each radioisotope has a characteristic ____, the time required for 50% of its atom to decay to a more stable state.

valence electrons

Electrons of the outermost shell, called _____ determine the chemical bonding properties of an atom.

isotopes

Elements have varieties calls ___ which differ from one another only in number of neutrons and therefore in atomic mass.

Trace elements

Elements that account for 0.7% of body weight, and no one of them accounts for more than 0.02%

Minerals

Enable enzymes and other organic molecules to functions

Exergonic

Energy-releasing reactions

adenosine triphosphatases (ATPases) adenosine diphosphate (ADP)

Enzymes called ____ are specialized to hydrolyze the third phosphate bond producing _____ and an inorganic phosphate group (Pi)

Ultraviolet rays x-rays alpha particles beta particles gamma rays

Examples of ionizing radiation include ___ and ____, and three kinds of radiation produced by nuclear decay:

Concentration temperature catalysts

Factors that affect reaction rates

Temperature and pH

Factors that change the shape of an enzyme that tend to alter or destroy the ability of the enzyme to bind to its substrate.

Saturated fatty acid

Fatty acid with a carbon forming a single bond to hydrogen. Has as much hydrogen as it can carry.

Essential fatty acids

Fatty acids that must be obtained from the diet because we cannot synthesize them.

fatty acids triglycerides phospholipids eicosanoids steriods

Five primary types of lipids in humans

Tertiary structure

Formed by the further bending and folding of protein into various globular and fibrous shapes. Van der Waals forces play a significant role in stabilizing this structure.

Prostaglandins

Functionally diverse eicosanoid that plays a variety of signaling roles.

isomers C6H12O6.

Glucose, fructose, and galactose are all ____ of each other with the molecular formula ____.

Disulfide bridges

Hold separate polypeptide chains together in such molecules as antibodies and insulin.

-OH sugars, alcohols

Hydroxyl functional group

Dehydration synthesis (condensation)

Hydroxyl group is removed from one monomer and a hydrogen from another producing water as a byproduct.

Electrolytes

Important for their chemical reactivity, osmotic effects, and electrical effects.

mutagenic carcinogenic

In lower doses, ionizing radiation can be ___ and ___

Dehydration synthesis

In triglycerides, each bond between a fatty acid and glycerol is formed by ___

Minerals

Inorganic elements that are extracted from the soil by plants and passed up the food chain to humans and other organisms. Make up 4% of the human body weight. (3/4 is Ca and P)

Guanosine triphosphate

Involved in energy transfers. Donates phosphate groups to other molecules.

Proteoglycans

Macromolecules in which the carbohydrate component is dominant and a peptide or protein forms a small component.

Oxygen Carbon Hydrogen Nitrogen

Major elements of the human body

Glycolipids glycoproteins

Many of the lipid and protein molecules at the external surface of the cell membrane have chains of up to 12 sugars attached to them, forming ___ and ___.

-CH3 Fats, oils, steroids, amino acids

Methyl functional group

Compounds

Molecules composed of two or more elements

Isomer

Molecules with identical molecular formulae but different arrangement of their atoms

Polymers monomers

Most macromolecules are _____, molecules made of a repetitive series of identical or similar subunits called ____

7.0 (H+=OH-)

Neutral pH

Neutrons

No charge

electrons

Number of protons equal the number of

change conformation, especially tertiary structure.

One of the most important properties of proteins is their ability to ____

Nucleotides

Organic compounds with three principal components: a single or double carbon-nitrogen ring called a nitrogenous base, a monsaccharide, and one or more phosphate groups. (ex. ATP)

Anion

Particle that gains electrons and acquires a negative charge

Cation

Particle that loses electrons and acquires a positive charge

Colloid

Particles that are too large to pass through most membranes, but small enough to remain mixed with the solvent. Particles are usually cloudy. 1-100nm in size. (Protein)

Suspension

Particles that are too large to pass through most membranes. Particles are too heavy and separate on standing. Exceed 100nm in size. (Blood cells)

-H2PO4 Nucleic acids, ATP

Phosphate

Phospholipids

Phosphate group linked to other functional groups. Amphipathic. Most important function is to serve as the structural foundation of cell membranes.

Reaction products

Product released by the enzyme in a chemical reaction.

Niels Bohn

Proposed a model of atomic structure similar to planets orbiting the sun.

Structure Communication Membrane transport Catalysis Recognition and protection Movement Cell adhesion

Protein functions

Enzymes

Proteins that function as biological catalysts. Enable biochemical reactions to occur rapidly at normal body temperature.

Ribonucleic acid (RNA)

Range from 70 to 10,000 nucleotides long. Carries out instructions given by DNA and synthesizes the proteins, assembles amino acids in the right order to product each protein describes by the DNA.

increases

Reaction rate ____ as the temperature rises.

Law of mass action

Reactions proceed from the reactants in greater quantity to the substances with the lesser quantity.

increase

Reactions rates ___ when the reactant are more concentrated.

Endergonic

Reactions that require an energy input

Ionic bond

Relatively weak attraction between an anion and a cation.

Covalent bond

Sharing of one or more pairs of electons between nuclei.

oligosaccharides polysaccharides

Short chains of three or more monosaccharides are called _____ and long chains (up to thousands of monosaccharides long) are called _____

Electrons

Single negative charge and very low mass.

Protons

Single positive charge

Functional groups

Small clusters of atoms that determine many of the properties of an organic molecule.

Hydrophilic

Substances that dissolve in water

Hydrophobic

Substances that do not dissolve in water.

Electrolytes

Substances that ionize in water (acids, bases, or salts) and form solutions capable of conducting electricity.

Catalysts

Substances that temporarily bind to reactants, hold them in a favorable position to react with each other, and may change the shape of reactants in ways that make them more likely to react. Speeds up reaction.

Disaccharides

Sugars compsed of two monosaccharides.

thermal stability

The ___ of water helps to stabilize the internal temperature of the body.

Lower = more hydrogen ions

The ___ the number = ___ hydrogen ions

Chemical reactivity

The ____ of water is its ability to participate in chemical reactions.

Biological half-life

The _____ of a radioisotope is the time required for half of it to disappear from the body.

Solvency

The ability to dissolve other chemicals

Calorie (cal)

The amount of heat that raises the temperature of 1 g of water to 1 degree C. The base unit of heat.

Quaternary structure

The association of two or more polypeptide chains by noncovalent forces such as ionic bonds and hydrophilic-hydrophobic interactions

protons and neutrons

The atomic mass of an element is equal to its total number of its ____

Adenosine triphosphate (ATP)

The body's most important energy-transfer molecule. Briefly stores energy gained from exergonic reactions and releases it with seconds for physiological work.

Energy

The capacity to do work.

Valence

The charge on an ion is called its

chemical equation left right

The course of a chemical reaction is symbolized by a _____ that shows reactants on the ____ and products on the _____.

Activation energy

The energy needed to get a reaction started

Starch

The energy-storage polysaccharide of plants.

Substrate

The enzyme identifies the substance it acts upon called its ____

Phosphorylation kinases

The free phosphate groups released by ATP hydrolysis are often added to enzymes or other molecules to activate them. This addition of Pi called ____, is carried out by enzymes called _____.

Enzyme substrate complex

The intermediate formed when a substrate molecule interacts with the active site of an enzyme.

Molarity

The number of moles of solute per liter of solution.

Oxidation-reduction (redox) reactions.

The oxidation on one molecule is always accompanied by the reduction of another. These transfers are known as

Free energy

The potential energy available in a system to do useful work.

radioactivity

The process of decay in radioisotopes is called

Primary structure

The protein's sequence of amino acids, which is encoded in the genes

Equilibrium

The ratio of products to reactants is stable.

Active site

The region of an enzyme where substrate molecules bind and undergo a chemical reaction.

monosaccharides

The simplest carbohydrates are monomers called ____ or simple sugars.

Element

The simplest form of matter to have unique chemical properties.

Biochemistry

The study of the molecules that compose living organisms.

Molecular weight (MW)

The sum of a compound's atomic weight of its atoms.

Cohesion

The tendency of molecules of the same substance to cling to each other.

Adhesion

The tendency of one substance to cling to another.

Sucrose (glucose + fructose) lactose (glucose + galactose) maltose (glucose + glucose)

The three primary disaccharides are ___

glucose fructose galactose

The three primary monosaccharides are ___

Polyunsaturated fatty acids

Those with many C=C bonds.

glycogen starch cellulose

Three examples of polysaccharides in human physiology

Exchange reaction

Two molecules exchange atoms of groups of atoms. AB + CD --> AC + BD

Synthesis reaction

Two or more small molecules combine to form a larger one. A + B --> AB

Ionic covalent hydrogen van der Waals forces

Types of chemical bonds

Radioisotopes

Unstable isotopes are called

Proteoglycan

Used for cell adhesion, lubrication, supportive filler of some tissues and organs

Solvency cohesion adhesion chemical reactivity thermal stability

Water's properties that account for its ability to support life.

Joined by polar covalent bonds V-shaped with a 105 degree angle

Water's structure

Hydrogen bond

Weak attraction between polarized molecules or between polarized regions of the same molecule. Important in the three-dimensional folding and coiling of large molecules. Easily disrupted by temperature and pH changes.

Van der Waals force

Weak, brief attraction due to random disturbances in the electron clouds of adjacent atoms. Weakest of all bonds.

anaerobic fermentation

When the demand for ATP outpaces the oxygen supply, excess pyruvic acid is converted to lactic acid by a pathway called ___

lock: active site key: substrate

Which is the active site and which is the substrate in the lock and key visual?

Alpha particles Beta partibles

____ are too large to penetrate the skin and ____ can penetrate only a few millimeters.

Nucleic acids

_____ are polymers of nucleotides