Anatomy & Physiology -- Chapter 2

BIOCHEMISTRY

•  It focuses on the chemical processes of living organisms

ELEMENT

• It is the simplest form of matter that has a unique chemical property

• The smallest unit of matter

IONS (anion, cation)

• Atoms or molecules that carry an electric charge due to the loss or gain of one or more electrons.

________: is a negative charge because it RECEIVES electrons

________: is a positive charge because it LOSES electrons

PROTON

• A positively charged subatomic particle found in the nucleus of an atom.

• It determines the atomic number and identity of an element.

NEUTRON

• A subatomic particle found in the nucleus of an atom that has no electric charge.

• They contribute to the atomic mass and stability of the nucleus.

ELECTRON

• A negatively charged subatomic particle that orbits the nucleus of an atom.

• ________ play a key role in chemical bonding and electricity.

• The number of _____ equals the number of protons, so their charges cancel each other out in neutral atoms, maintaining overall charge balance.

VALENCE ELECTRONS

• Electrons in the outermost shell of an atom that are involved in chemical bonding.

• They determine an element's reactivity and bonding behavior.

ELECTROLYTES

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

• ________ balance is one of the most important considerations in patient care, imbalance can lead to serious health issues like muscle cramps, brittle bones to a coma and/or cardiac arrest

FREE RADICALS

• Unstable, highly reactive chemical particles with an odd number of electrons

• Are produced by some normal metabolic reactions, by radiation, and by chemicals.

ANTIOXIDANTS

• Neutralizes free radicals

MOLECULE

• Particles composed of two or more atoms united by a chemical bond

COMPOUND

• Molecules composed of two or more elements chemically bonded together.

CHEMICAL BOND

• Holds together within the molecule or attracts one molecule to another

HYDROGEN BOND

• A weak attraction between a slightly positive hydrogen atom in one molecule and a slightly negative oxygen or nitrogen atom in another

MIXTURES

• Consists of substances that are physically blended but not chemically combined; each substance retains its own chemical properties.

WATER

• 50% to 75% of one’s body weight (approx.)

• Water has a variety of properties that support life:

  • Solvency (the ability to dissolve other chemicals), Cohesion (the tendency of molecules of the same substance to cling to each other), Adhesion (the tendency of one substance to cling to another), Chemical Reactivity (the ability to participate in chemical reactions), and Thermal Stability (helps to stabilize the internal temperature of the body)

HYDROPHILIC

• Molecules that attract water

• Dissolve in it because of their polar nature

HYDROPHOBIC

• Molecules that do not attract water

• They do not dissolve in it because of their nonpolar nature, molecules tend to dissolve in lipids and other nonpolar solvents

SOLUTIONS

• Consists of particles of matter called the solute mixed with a more abundant substance (usually water) called the solvent.

• Solute can be a gas, solid, or liquid

SOLUTIONS (properties)

• Under 1nm

• Cannot be visually distinguished

• Small particles don’t scatter light, they are usually transparent

• They can pass through the most selectively permeable membranes

• Doesn’t separate from the solvent when the solution is allowed to stand

COLLOIDS

• Mixtures of protein and water

• They often change from a liquid to a gel state

  • Gelatin desserts, agar culture media, and fluids between cells

COLLOIDS (properties)

• 1 to 100 nm in size

• Particles scatter light, usually cloudy

• Too large to pass the most selectively permeable membranes

• Yet small enough to remain permanently mixed with the solvent when the mixture stands

SUSPENSIONS (properties)

Ex: blood plasma, settle to the bottom of the tube

• EXCEED 100 nm in size

• Large particles that are cloudy or opaque

• Too large to penetrate selectively permeable membranes

• TOO HEAVY to remain permanently suspended, they separate on standing

ACID

• Proton DONOR, releases a proton (H+) in water

BASE

• Proton ACCEPTOR, accepts H+ ions OR releases OH- ions in water

pH

• a measure derived from the molarity of H+

• pH of 7.0 = neutral

• pH < 7 = acidic

• pH > 7 = basic (alkaline)

The lower the pH, the more hydrogen ions a solution has and the more acidic it is.

ENERGY

• The capacity to do work

• To move something, whether a muscle or a molecule

Ex: breaking chemical bonds, building molecules, pumping blood, and contracting skeletal muscles

POTENTIAL ENERGY

• Energy contained in an object, at the moment, not doing anything that’s releasing energy

KINETIC ENERGY

• Energy of motion, energy that is doing work

• HEAT

CHEMICAL ENERGY

• Potential energy stored in the bonds of molecules

• Reactions release this energy and make it available for physiological work

FREE ENERGY

• The potential energy in a chemical that is available to do work

CATABOLISM

• Consists of energy-releasing decomposition reactions

• Energy-releasing is also called EXERGONIC

ANABOLISM

• Consists of energy-storing synthesis reactions, such as the production of protein or fat

• Reactions REQUIRE an energy input, they are called ENDERGONIC

METABOLISM

• All the chemical reactions in the body

• 2 divisions:

  • Catabolism & Anabolism

OXIDATION

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

ORGANIC CHEMISTRY

• The study of compounds of carbon

DEHYDRATION SYNTHESIS

• Creating a new covalent bond between two monomers and producing water as a by-product

HYDROLYSIS

• Consuming a water molecule to break a covalent bond

• When water ionizes itself into H+ and OH-

CARBOHYDRATES

• Hydrophilic organic compound composed of carbon and a 2:1 ratio of hydrogen to oxygen; includes sugars, starches, glycogen, and cellulose

• Quicker source of energy

• Oxidized to make ATP

MONOSACCHARIDES

• Simplest carbohydrate monomer

• Simple sugar

  • glucose, galactose, fructose

DISACCHARIDES

• Sugars composed of TWO monosaccharides

  • sucrose, lactose, and maltose

POLYSACCHARIDES

• Long chains (up to thousands of monosaccharides long)

• A chain of 50 or more

GLYCOGEN

• Energy-storage polysaccharides made by cells of the liver, muscles, brain, uterus, and vagina

LIPIDS

• Is a HYDROPHOBIC molecules, usually composed only for carbon, hydrogen, and oxygen

  with a high ratio of hydrogen and oxygen

FATTY ACIDS

• Source of energy

• 4 to 24 carbon atoms with a carboxyl group at one end and a methyl group at the other

PHOSPHOLIPIDS

• ____________ are the major component of the cell membrane; they help in fat digestion, have a hydrophobic tail that helps with fluidity, and the head helps with the membrane surface charge and intracellular signaling APR 

CHOLESTEROL

• Strengthens the membrane and stabilizes it at extreme temperatures.

• Prevents over-dense packing of fatty acid tails by filling gaps between fatty acid tails APR

PROTEINS

• a polymer of amino acids

ENZYMES

• Are macromolecules that function as biological catalysts

• Found in the ribosomes

ATP

• The body’s most important energy-transfer molecule

• Is the most important energy supplier 

• Stores energy from EXERGONIC reactions 

  • It is released when doing work

NUCLEOTIDES

• Compounds with three principal components: a nitrogenous base, a monosaccharide, and a phosphate group; the monomer of a nucleic acid

NUCLEIC ACIDS

• Polymers of nucleotides

• Found or produced in the nucleus, functioning in heredity and protein synthesis; of two types, DNA & RNA