The Chemical Level of Organization (Lecture 2)

Unit Exam 1

Which two systems control most body parts?

Nervous and endocrine system

Kinetic energy

energy in motion

Chemical energy

chemical bonds in molecules

Electrical energy

from moving electrical charge

Hierarchy

Atom, molecule, organelle, cell, organ, organ system

4 major elements that make up 96% of body

Carbon, Hydrogen, Oxygen, Nitrogen (CHON)

Octet rule

8 valence electrons

First shell can hold __ electrons, the rest can hold up to __ electrons

2; 8

Ionic bond

Transfer of electrons, results in two charged ions (Na+ Cl-), bigger number will steal

Non-polar covalent bond

Equal sharing of electrons, no charge (O = O)

Polar covalent bond

Unequal sharing of electrons, partial charge (within one water molecule/H2O)

Hydrogen bond

Attraction between partial positive and negative charges → bonds that give molecules their 3D shape (Shape of DNA and proteins between water molecules)

Major cation

Sodium

Major anion

Chloride

Anabolism (chem reaction)

(synthesis) reactions, building, requires energy (ex: steroids)

Ex: amino acids join together to make protein

Catabolism (chem reaction)

(decomposition) reactions, breaking down, releases energy (ex: hurricane/catastrophe)

Ex: polysaccharide eaten broken down = monosacch glucose

Water makes up _____ of living organisms

60%-80%

Organic vs inorganic molecules

Org: carbon + hydrogen atoms; anything living has organs

Inorg: carbon OR hydrogen; never living (plastic)

Solution

liquid mixture of two or more substances

Solute

a dissolved substance in liquid

Solvent

able to dissolve other substances (water can break up protein, sugars, salts)

Hydrophilic molecules

Water-loving, attraction to water, dissolves readily in water (ions and polar molecules)

Hydrophobic molecules

Water-fearing, no attraction to water, do not dissolve in water (uncharged and nonpolar molecules)

Acids on pH scale

below 7

Bases/alkalines on pH scale

over 7

Which two parts of human body are more acidic?

Inside the stomach and urine

Salts when dissolved in water dissociate into?

Cations and anion

Electrolytes

minerals in the body’s blood and other fluids that have an electic charge when dissolved

Homeostatic regulation

all cells of the body depend on a balanced pH of 7.4; body has regulation methods: breathing, excreting chemicals in urine, and internal release of chemicals into body fluids

4 Carbon Compounds

Carbohydrates, proteins, lipids, nucleotides/nucleic acids

3 types of carbohydrates

Monosaccharides, disaccharides, polysaccharides

Monosaccharides

Glucose (subunit of most polysaccharides, found in the blood)

Fructose (found in corn syrup and many fruits and vegetables)

Galactose (milk sugar)

Disaccharides

Sucrose (glucose+fructose=table sugar)

Lactose (glucose+galactose=milk sugar)

Maltose (glucose+glucose=forms in digestive tract)

Polysaccharides

Starch (chain of glucose monomers; energy storage in plants)

Glycogen (chain of glucose monomers; energy storage in animals)

Cellulose (in plant cell walls, humans cannot digest, fiber in our diet)

Cholesterol

needed fats (not bad as whole)

LDL = bad cholesterol

HDL = good cholesterol

Steroid hormones

Estrogen, progesterone, testosterone (made from cholesterol)

Peptide bonds

short chain; amino group of one amino acid is joined to carboxyl group of another amino acid

Polypeptide chain or protein

long chain of amino acids (usually 50 or more amino acids in length)

Enzymes

important proteins that function as biological catalysts; help speed up metabolism; bind to specific substrates to create an action

Nucleic acids

DNA & RNA; DNA cell of living things; long chains of subunits known as nucleotides

Nucleotides

the building blocks of all nucleotides are one or more phosphate groups, a pentose sugar, and a nitrogenous base

DNA

genetic blueprint made up of chromosomes and exists in the nucleus of all living cells; bonds to CGAT

RNA

transmits genetic information from the DNA in the nucleus to the cytoplasm of the cell and functions in the synthesis of proteins; base pairing CGAU

3 types: messenger, ribosomal, transfer

ATP

energy currency of the cell; stores energy from reactions and releases it within seconds for work

Mitochondria produces ATP

Cellular respiration where glucose is converted to ATP