kin exam1-2

Homeostasis

Maintenance of a relatively stable internal environment

Regulated variable

A variable the body controls such as temperature or blood glucose

Internal environment

The extracellular fluid surrounding cells

External environment

Everything outside the body

Four classifications of cells

Muscle, nerve, epithelial, and connective tissue cells

Organization of body systems

Cells to tissues to organs to organ systems to organism

TBW

Total body water in the body

ICF

Fluid inside cells; about two-thirds of TBW

ECF

Fluid outside cells; about one-third of TBW

Plasma

Fluid portion of blood

ISF

Fluid between cells

Negative feedback loop

Control system that returns a variable to its normal range

Importance of homeostasis

Allows cells and organs to function properly

Diabetes

Disorder of impaired blood glucose regulation

Covalent bond

Bond formed by sharing electrons

Polar molecule

Unequal sharing of electrons; hydrophilic

Nonpolar molecule

Equal sharing of electrons; hydrophobic

Four biomolecules

Carbohydrates, lipids, proteins, nucleotides

Carbohydrates

Glucose monomer; stored as glycogen; primary energy source

Lipids

Triglycerides, phospholipids, and steroids

Proteins

Made of amino acids; function as enzymes, structure, transport

Nucleotides

ATP for energy and DNA or RNA for genetic information

Metabolism

All chemical reactions in the body

Anabolism

Energy requiring reactions that build molecules

Catabolism

Energy releasing reactions that break molecules down

1st Law of Thermodynamics

Energy cannot be created or destroyed

2nd Law of Thermodynamics

Energy transformations increase entropy

Endergonic reaction

Requires energy input

Exergonic reaction

Releases energy

Law of Mass Action

Reaction direction depends on reactant and product concentrations

Enzymes

Proteins that lower activation energy

ATP

Primary energy currency of the cell

ATP-CrP system

High intensity, short duration energy system

Glycolysis

Breakdown of glucose to produce ATP

Krebs Cycle

Produces NADH and FADH2 in the mitochondria

Electron Transport Chain

Produces most ATP and requires oxygen

Role of oxygen

Final electron acceptor in the electron transport chain