Anatomy & Physiology Bio 168: Chapter 2

ATP

(adenosine triphosphate) main energy source that cells use for most of their work.

Cyclic adenosine monophosphate (cAMP)

(cAMP) A nucleotide formed by the removal of both the second and third phosphate groups from ATP

Photons

-Packets of light energ

Cell adhesion

-cells adhere to one another and to extracellular material through membrane protein

Reaction rates increase when...

-the reactants are more concentrated -the temperature rises -a catalyst is present

Effective coolant

1 ml of perspiration removes 500 calories

24 elements have biological role

24 elements that make up the human body

Carbon has how many valence electrons

4

Fatal Radiation

5 Sv

Water is

50% to 75% of body weight

Oxidation

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

Tertiary structure

A coiling or bending of the secondary structure. Involves: Hydrogen, Ionic, & Covalent (disulfide)bonds, as well as hydrophobic interactions:

Nonpolar Bond

A covalent bond in which electrons are shared equally.

Molecule

A group of atoms bonded together

Suspension

A mixture in which particles can be seen and easily separated by settling or filtration

Neutron

A particle found in the nucleus with mass similar to the proton but with zero electric charge.

Ion

A particle that is electrically charged (positive or negative)

Protons

A positively charged particle in the nucleus of an atom

element

A pure substance made of only one kind of atom

Compound

A substance consisting of two or more elements in a fixed ratio.

Trace Elements

An element indispensable for life but required in extremely minute amounts.

Reduction

Any chemical reaction in which a molecule gains electrons and energy

Coenzymes

Are organic cofactors commonly derived from soluble water vitamins.

Isotopes

Atoms of the same element that have different numbers of neutrons.

Ionic Bonds

Attractions between anions and cations (example, NaCl) Electrons donated from one atom to another Easily broken by water

Enzymes

Biological catalysts lower activation energy

Catabolism

Break down of materials, Breaks bonds, releases energy

Reversible reactions

Can go in either direction determined by the abundance of substances on each side of the equation; represented by paired arrows

Four categories of carbon compounds

Carbohydrates Lipids Proteins Nucleic acids

6 elements that make up 98.5% of body weight

Carbon, Hydrogen, nitrogen, oxygen, phosphorus, and sulfur

Regulation of metabolic pathways

Cells can turn on or off pathways when end products are needed or unneeded

Free Radicals

Chemical particles with an odd number of electrons Trigger reactions that destroy molecules, and can cause cancer, death of heart tissue, and aging

Antioxidants

Chemicals that neutralize free radicals

Biochemistry

Chemistry of living things

Secondary structure

Coiled or folded shape held together by hydrogen bonds

Cofactors

Compounds that combine with an inactive enzyme to form an active enzyme.

Isomers

Compounds that have the same molecular formula but different structures.

Nucleic Acids

DNA and RNA

Classes of chemical reactions

Decomposition reactions Synthesis reactions Exchange reactions

Ionizing

Ejects electrons, destroys molecules, creates free radicals. Can cause cancer or mutations

Valence electrons

Electrons in the outermost energy level of an atom

Kinetic energy

Energy of motion.

Ionization

Energy required to remove an electron from a gaseous atom

Potential energy

Energy that is stored and held in readiness

Heat

Energy that is transformed as a consequence of temperature differences

Anabolism

Energy-storing (endergonic) synthesis reactions -Requires energy input -Production of protein or fat

Glycolipids

External surface of cell membrane

Glycoproteins

External surface of cell membrane

Denaturation

Extreme conformational change that destroys function

Five primary lipid types in humans

Fatty acids Triglycerides Phospholipids Eicosanoids Steroids

Molecular formula

Gives the actual number of atoms of each element in a molecule of a compound.

Three important monosaccharides

Glucose, galactose, and fructose Produced by digestion of complex carbohydrates

three key examples of Polysaccharides

Glycogen—energy storage in cells of liver, muscle, brain, uterus, vagina Starch—energy storage in plants that is digestible by humans Cellulose—structural molecule in plants that is important for human dietary fiber (but indigestible to us)

Structure

How the body is put together keratin and cartilage

Radioisotopes

Intense radiation can be ionizing

Electrons

Light negatively charged particles that orbit around nucleus. (clouds)

Atomic number

Number of protons in an atom

Single Covalnt Bond

One pair of electrons shared

Oxidation-reduction (redox) reactions

Oxidation of one molecule is always accompanied by reduction of another

Suspension physical properties

Particles exceed 100 nm Too large to penetrate selectively permeable membranes Cloudy or opaque in appearance Separates on standing Example: blood cells are suspended in plasma

Colloids are defined by the following physical properties:

Particles range from 1-100 nm in size Scatter light and are usually cloudy Particles too large to pass through semipermeable membrane Particles remain permanently mixed with the solvent when mixture stands

Primary structure

Protein's sequence of amino acids which is encoded in the genes

Solutions are defined by the following properties:

Solute particles under 1 nm Solute particles do not scatter light Will pass through most membranes Will not separate on standing

Communication

Some hormones and other cell-to-cell signals are proteins Ligand—a molecule that reversibly binds to a protein Receptors to which signal molecules bind are proteins

Organic chemistry

Study of carbon compounds

Three important disaccharides

Sucrose—table sugar Glucose + fructose Lactose—sugar in milk Glucose + galactose Maltose—grain products Glucose + glucose

Emulsion

Suspension of one liquid in another Example: fat in breast milk is an emulsion

Calorie (cal)

The amount of energy necessary to raise the temperature of 1 g of water by 1°C.

heat capacity

The amount of energy needed to raise the temperature of substance by one degree Celsius

Peptide bond

The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid

Quaternary structure

The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits

Molarity (M)

The number of moles of solute per liter of solution

Double Covalent Bonds

Two pairs of electrons shared

Sievert (Sv)

Unit of radiation dosage

Hydrogen bond

Weak attraction between a slightly positive hydrogen atom and a slightly negative atom.

Polar Bond

a covalent bond in which electrons are not shared equally

Protein

a polymer of amino acids

Van der Waals forces

a slight attraction that develops between the oppositely charged regions of nearby molecules

Solvency

ability to dissolve other chemicals

Chemical reactivity

ability to participate in chemical reactions

ATP contains

adenine, ribose, and 3 phosphate groups

Metabolism

all chemical reactions of the body

Guanosine triphosphate (GTP)

an energy transfer molecule similar to ATP that releases free energy with the hydrolysis of its terminal phosphate group

Structural formula

an expanded molecular formula showing the arrangement of atoms within the molecule

electrically neutral

an object that has equal amounts of positive and negative charges

Recognition and protection

antibodies and other proteins attack and neutralize organisms that invade the body

Peptide

any molecule composed of two or more amino acids joined by peptide bonds

Ions with opposite charges

are attracted to eachother

Isotopes of an element

are chemically similar because they have the same number of valence electrons

Solute

can be gas, solid, or liquid

Energy

capacity to do work

Carbon atoms bind readily with each other to form

carbon backbones

carbon backbones

carry a variety of functional groups

Nucleus

center of atom

Amino acid

central carbon with three attachments

Electrolyte Importance

chemical reactivity, osmotic effects, electrical effects on nerve and muscle tissue

Solution

consists of particles called the solute mixed with a more abundant substance (usually water) called the solvent

Conjugated carbohydrate

covalently bound to lipid or protein moiety

Hydrolysis

digestion; the opposite of dehydration synthesis

Law of mass action

direction of reaction determined by relative abundance of substances on either side of equation

"Good" and "bad" cholesterol

droplets of lipoprotein in the blood

planetary model

electrons move around the nucleus in fixed, circular orbits

Reusability of enzymes

enzymes are not consumed by the reactions

Electrolytes measured in

equivalents (Eq)

Polar covalent bonds and a V-shaped molecule

give water a set of properties that account for its ability to support life.

glucose amu

glucose weighs 180 amu; A 1M solution of glucose contains 180 g of glucose in 1 L of solution

Water's thermal stability

helps stabilize the internal temperature of the body

"good" cholesterol

high density lipoproteins HDL Lower ratio of lipid to protein

Chemical bonds

hold atoms together within a molecule or attract one molecule to another

Water is involved in

hydrolysis and dehydration synthesis reactions

Lipids

hydrophobic organic molecules with a high ratio of hydrogen to oxygen Have more calories per gram than carbohydrates

minerals

inorganic elements extracted from soil by plants and passed up food chain to humans

Catabolism and anabolism are

inseparably linked Anabolism is driven by energy released by catabolism

Most important types of chemical bonds

ionic bonds, covalent bonds, hydrogen bonds, van der Walls forces

pH

is a measure derived from the molarity of H+

base

is a proton acceptor (accepts H+ ions) Many bases release OH-

acid

is a proton donor (releases H+ ions in water)

Glucose

is blood sugar

Dehydration synthesis

is how living cells form polymers monomers covalently bind together to form a polymer with the removal of a water molecule

molecular weight (MW) of a compound

is the sum of the atomic weights of its atoms.

Polymerization

joining monomers to form a polymer

Polysaccharides

long chains of monosaccharides (at least 50);

"bad" cholesterol

low density lipoproteins LDL High ratio of lipid to protein

Polymers

macromolecules made of a repetitive series of identical or similar subunits (monomers)

Electrolytes

mineral salts needed for nerve and muscle function

Reactions occur when

molecules collide with enough force and correct orientation

Motor proteins

molecules with the ability to change shape repeatedly

Proteoglycans

more carbohydrate than protein Gels that hold cells and tissues together

Membrane transport

movement of substance into and out of the cell

Colloids

often mixtures of protein and water

Surface film

on surface of water is due to molecules being held together by surface tension

Astonishing speed

one enzyme molecule can consume millions of substrate molecules per minute

electrolyte balance

one of most important considerations in patient care.

Amino acids differ

only in the R group

Attractions to water molecules

overpower the ionic bond in NaCl Water forms hydration spheres around each ion and dissolves them Water's negative pole faces Na+, its positive pole faces Cl-

Anion

particle that gains electron(s) (net negative charge

cation

particle that loses electron(s) (net positive charge)

Three components of nucleotides

phosphate group, pentose sugar, nitrogeneous base

Mixtures

physically blended but not chemically combined

Free energy

potential energy available in a system to do useful work

Chemical energy

potential energy in molecular bonds

equilibrium

reached when ratio of products to reactants is stable

Decomposition reactions

reactions—large molecule breaks down into two or more smaller ones AB A + B

Chemical reaction

reaction—a process in which a covalent or ionic bond is formed or broken

A change of one number on the pH scale

represents a 10-fold change in H+ concentration

Oligosaccharides

short chains of 3 or more monosaccharides (at least 10)

Functional groups

small clusters of atoms attached to carbon backbone

Metabolic reactions depend on

solvency of water

Carbohydrates are a quickly mobilized

source of energy

Substrate

substance enzyme acts upon ase as the suffix

Hydrophilic

substances that dissolve in water Molecules must be polarized or charged (e.g., sugar)

Hydrophobic

substances that do not dissolve in water Molecules are nonpolar or neutral (e.g., fats)

Enzyme action

substrate fits on active site, enzyme releases product, forms back to original shape, ready to act again

Disaccharide

sugar made of two monosaccharides

Chemical equation

symbolizes the course of a chemical reaction Reactants (on left) products (on right)

Cohesion

tendency of like molecules to cling to each other

Adhesion

tendency of one substance to cling to another

Cholesterol

the "parent" steroid from which other steroids are synthesized 15% of our cholesterol comes from diet

electromagnetic energy

the kinetic energy of moving "packets" of radiation called photons

Physical half-life

time it takes for 50% of the radioisotope to become stable

Biological half-life

time required for 50% of radioisotope to clear from body

Exchange reactions

two molecules exchange atoms or group of atoms AB+CD ABCD AC + BD

Synthesis reactions

two or more small molecules combine to form a larger one A + B AB

Conformation

unique, three-dimensional shape of protein crucial to function

Macromolecules

very large organic molecules with high molecular weights

universal solvent

water

Weight per volume

weight of solute in given volume of solution