Anatomy & Physiology Chapter 1-4 Mcgraw Hill

Homeostasis

process by which organisms maintain a relatively stable internal environment

Receptor

body structure that monitors changes in a controlled condition and sends input to a control center

Stimulus

a signal to which an organism responds

control center

processes the signal and sends instructions

Effector

an organ or cell that acts in response to a stimulus.

negative feedback

A primary mechanism of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.

positive feedback

Feedback that tends to magnify a process or increase its output until a climatic event occurs.

An example of negative feedback

Controlling body temperature

An example of positive feedback

A mother breastfeeding

An example of homeostasis imbalance

Diabetes

What is an SSRI?

Selective Serotonin Reuptake Inhibitor; an example of this is Serotonin, which is a neurotransmitter.

organic compounds

Compounds that contain carbon

inorganic compounds

Compounds that do not contain carbon

Examples of organic compounds

carbohydrates, lipids, proteins, nucleic acids

examples of inorganic compounds

water, salts, acids, bases

Properties of water

High heat capacity, high heat of vaporization, polar solvent, reactivity, cushion

Acid

A substance that increases the hydrogen ion concentration of a solution (H+)

Base

A substance that decreases the hydrogen ion concentration in a solution (OH-)

As a liquid, how does water serve as a function in the body?

Transportation, lubrication, cushioning, and excretes wastses.

What kind of a solvent is water?

universal solvent - polar

What kind of substances dissolve in water?

polar molecules (glucose) and ions (Na+)

Hydrophobic

Water fearing

Hydrophilic

Water loving

Why do polar molecules dissolve in water better than others?

Because of the hydrogen bonds that form between those molecules and water molecules.

What is dissociation?

the process in which an ionic compound separates into ions as it dissolves

Electrolyte

An ionic compound whose aqueous solution conducts an electric current (salts, acids, bases).

polar

Molecule with partial charges. Mixes with water.

nonpolar

No partial charges. Do not mix with water.

proton donor

acid

proton acceptor

base

Acids scale

0-6

Bases scale

8-14

What kind of pH does pure water have?

7

Neutralization

When an acid and base mix to make a neutral substance

Buffer

compound that prevents sharp, sudden changes in pH

Triglycerides

an energy-rich compound made up of a single molecule of glycerol and three molecules of fatty acid.

dehydration synthesis

A chemical reaction in which two molecules are bonded together with the removal of a water molecule.

Hydrolysis

Breaking down complex molecules by the chemical addition of water

Lipids

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen (insoluble in water).

major classes of lipids

triglycerides, phospholipids, steroids

Saturated

Fats with the maximum number of hydrogens.

Unsaturated

Fat with less than the maximum number of hydrogens in one or more of its fatty acid chains

polyunsaturated

two or more double bonds

Lipogenesis

the metabolic formation of fat

Lipolysis

breakdown of fat

Phospholipids

a lipid consisting of a glycerol bound to two fatty acids and a phosphate group (modified triglycerides; important to cell membrane structure)

Steroids

lipids characterized by a carbon skeleton consisting of four fused rings including and derived from cholesterol

Carbohydrates

hydrated carbon atoms; the starches and sugars present in foods

Monosaccharides

Single sugar molecules (galactose, fructose, ribose, deoxyribose). Can be five or six-carbon sugars

Disaccharides

Carbohydrates that are made up of two monosaccharides (sucrose, lactose, maltose).

Glucose

A simple sugar that is an important and common source of energy.

Glycogen

An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.

Glycogenesis

formation of glycogen from glucose

Glycogenolysis

breakdown of glycogen to glucose

nucleic acids

biological molecules, such as DNA or RNA, composed of nucleotides that control cellular functions and heredity.

Nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

Prymidines

single-ring nitrogenous bases (thymine, cytosine, uracil)

Purines

double ring nitrogenous bases (adenine and guanine)

deoxyribonucleic acid (DNA)

A double-stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins.

Nitrogenous bases in DNA

adenine, guanine, cytosine, thymine

Nitrogenous bases in RNA

adenine, guanine, cytosine, uracil

ribonucleic acid (RNA)

single-stranded nucleic acid that contains the sugar ribose, located within the cell nucleus and cytoplasm.

Adenosine Triphosphate (ATP)

compound used by cells to store and release energy (composed of the nitrogenous base adenosine and a ribose sugar)

Proteins

polymers composed of one or more linear stands of amino acid monomers.

amino acids

building blocks of proteins

peptide bond

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

primary structure of protein

linear sequence of amino acids

secondary structure of a protein

protein structure is formed by folding and twisting of amino acid chain, resulting in an alpha helix or beta pleated sheet

tertiary structure of protein

3D shape of protein with repeated secondary structures to form globular or fibrous protein

quaternary structure of a protein

a molecule composed of two or more separate proteins

protein denaturation

when proteins are subject to heat, acid or other conditions that disturb their stability; protein uncoils, loses its shape, and loses its function

Catalysts

Chemical agents that selectively speed up chemical reactions without being consumed by the reaction.

Enzymes

Catalysts for chemical reactions in living things

active site

The part of an enzyme or antibody where the chemical reaction occurs.

Substrate

A specific reactant acted upon by an enzyme

enzyme-substrate complex

A temporary complex formed when an enzyme binds to its substrate molecule(s).

decomposition reaction

a reaction in which a single compound breaks down to form two or more simpler substances

synthesis reaction

a reaction in which two or more substances combine to form a new compound

Saturation

the state or process that occurs when no more of something can be absorbed, combined with, or added within enzyme reactions.

Effects of temperature on enzymes

if temp is too low enzymes slow down, if temp is too high causes denaturation but a high tolerable temp causes enzymes to work faster (optimum temperature)

Effects of pH on enzymes

Different enzymes have different optimum pHs, at extreme pHs, enzymes become denatured

Inhibitors of enzymes

substances that bind to enzymes to stop enzyme activity, turning it off.

competitive inhibitor

resembles the substrate and binds to the active site of the enzyme

noncompetitive inhibitor

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.

allosteric site

A site on an enzyme other than the active site, to which a specific substance binds, thereby changing the shape and activity of the enzyme.

metabolic pathway

A series of chemical reactions that either builds a complex molecule or breaks down a complex molecule into simpler compounds.

multienzyme complex

a group of enzymes, each of which catalyzes one reaction, that are physically joined to each other

Multienzyme complex advantages

-Less likely substance will diffuse away into different biochemical pathway

-Single complex can be regulated rather than individual enzymes

cells

The basic unit of structure and function in all living things; considered the functional units of the body

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

interstitial fluid

fluid between cells

phospholipid bilayer

Plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside.

Cholesterol

A lipid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids.

Glycolipids

Membrane carbohydrates that are covalently bonded to lipids.

integral proteins

spans the entire membrane

peripheral proteins

bound to the surface of the membrane

membrane protein functions

Transport proteins, cell surface receptors, identity markers, enzymes, anchoring sites, cell-adhesion proteins

Types of transport proteins

channel, pump, and carrier protein

passive transport

the movement of substances across a cell membrane without the use of energy by the cell (moving down the concentration gradient)

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference (moving against the concentration gradient) (also uses carrier proteins and solute pumps)