ch 2 a&p1 (copy)

4 Major Elements in body

4 Major Elements in body

Oxygen, carbon, nitrogen, and hydrogen

Atom Structure

Atoms consist of protons and neutrons in the nucleus, with electrons surrounding it.

Electron Shell

A region around the nucleus where electrons are found; 1st shell holds 2 e-, 2nd shell holds 8 e-, 3rd shell holds 18 e-.

Atomic Number

The number of protons in the nucleus; defines the element

mass number

sum of proton and neutrons

Isotope

Atoms of the same element differing in neutron number; e.g., C12 and C13.

Ion

An atom that has lost or gained electrons

Molecule

2 or more atoms changing electrons or chemically bonding

Compound

A substance containing atoms of two or more different elements.

3 different types of chemical bonds

ionic bond, covalent bond, hydrogen bond

ionic bond

A bond between positively and negatively charged ions, e.g., NaCl.

Covalent Bond

A bond formed when atoms share electrons, e.g., H-H.

Hydrogen Bond

polar covalent bond that form between H atom and other atoms, e.g., water molecules bonding together.

Potential Energy

Energy stored in matter, e.g., a car at a stop sign.

Kinetic Energy

Energy of matter in motion, e.g., a car moving at a green light.

Chemical Energy

Potential energy stored in the bonds of compounds and molecules.

Exergonic Reaction

A reaction that releases energy as heat; bond breaking has more energy than bond forming.

Endergonic Reaction

A reaction that requires energy to form a bond; absorbs more energy than released.

Activation Energy

The energy needed to break bonds; influenced by concentration and temperature.

Enzymes

Proteins that speed up reactions by lowering activation energy; catalysts are compounds that do the same.

Catabolism

Breakdown of complex compounds into simpler substances, releasing energy (exergonic).

catalyst

chemical compounds that speed up chemical reactions by lowering the activation energy needed for a reaction to occur

Anabolism

Building new molecules and storing energy in ATP (endergonic).

Synthesis Reaction

Two or more reactants combine to form a complex substance, e.g., dehydration synthesis/ removal of water

Decomposition Reaction

A complex substance breaks down into smaller substances, e.g., hydrolysis.

Exchange Reaction

A reaction involving both synthesis and decomposition, e.g., HCl + NaHCO3 → NaCl + H2CO3.

Most Important Inorganic Compound in all living things

Water

Solution

A mixture where solutes are evenly dispersed in a solvent (transparent).

Colloid

A mixture with larger particles that scatter light (opaque).

Suspension

A mixture where particles may settle out over time (e.g., blood).

Acids

Substances that ionize to produce 2 or more H+ and 1 or more anion

pH Scale

Ranges from 0 to 14; 7 is neutral, below 7 is acidic, above 7 is basic.

Organic Compounds

All contain carbon.

Four Organic Macromolecules

Carbohydrates, lipids, proteins, and nucleic acids.

Carbohydrate Groups

Monosaccharides, disaccharides, and polysaccharides.

Lipid Families

Fatty acids, triglycerides, phospholipids, and steroids.

Triglyceride Composition

Made of 1 glycerol molecule and 3 fatty acids;

what chemical reaction forms triglycerides

dehydration synthesis reaction

Saturated Fatty Acid

Contains only single covalent bonds (solid).

Unsaturated Fatty Acid

Contains one or more double covalent bonds (liquid).

Phospholipids

Major lipid component of cell; aka plasma membranes

what makes up a phospholipid

polar phosphate head, a glycerol backbone, and two non-polar fatty acid tails.

where can you find phospholipids?

phospholipid bilayer

Protein Functions

Structure, enzymes, muscular contraction, and antibodies, hormones

Protein Components

Made of amino acids

protein bonds

peptide bonds

Functional Groups in Proteins

Amino group (NH2), carboxyl group (COOH), and R group.

Protein Structures

Primary, secondary, tertiary, and quaternary structures.

Primary structure of proteins

unique sequence of amino acids that are linked by covalent peptide bonds to form a polypeptide chain

secondary structure of proteins

repeated twisting and folding of neighboring amino acids in polypeptide chain

tertiary structure of proteins

3D shaped of polypeptide chain. Each protein has uniquely tertiary structure that determines how it will function

quaternary structure

Arrangement of the individual polypeptide chains relative to one another (arrangement of 2 or more polypeptide chains

Enzyme Function

Lowers activation energy (speed up process) by forming an enzyme-substrate complex.

enzymes end in

-ase

nucleic acids

DNA & rNA

DNA

Double-stranded, contains genetic code; composed of nucleotides with deoxyribose sugar.

DNA NUCLEOTIDE UNITS

A-T C-G

RNA NUCLEOTIDE UNITS

A-U C-G

RNA

Single-stranded, involved in protein synthesis; composed of nucleotides with ribose sugar.

Basic Units of Nucleic Acids

Nucleotides (C, H, N, O, P).

Parts of Nucleotides

Nitrogenous base, pentose sugar, and phosphate group.

cation

electron donor; given 1 or more electron

anion

electron acceptor; picked up 1 or more electron

ATP

energy storing mol. consist of 3 phosphate groups attached to adenosinea

adenosine

unit composed of adenine and 5-C sugar ribose