Mammalian Physiology Chapter 2

What makes up more than 90% of the body’s mass?

Oxygen, Carbon, and Hydrogen

What are organic molecules?

Molecules that contain carbon

What are biomolecules?

Organic molecules associated with living organisms

What are the four major groups of biomolecules?

Carbohydrates, lipids, proteins, and nucleotides

What are DNA and RNA?

Structural components of genetic material

What is ATP?

Adenosine Triphosphate, it carries energy

What is cAMP?

Cyclic AMP (adenosine monophosphate) regulate metabolism

What are conjugated proteins?

Protein molecules combines with another kind of biomolecule

What are lipoproteins?

Proteins that combine with lipids

Where are lipoproteins found?

Lipoproteins are found in the cell membranes and in the blood, where they act as carriers for less soluble molecules, such as cholesterol

What is a glycosylated molecule?

Molecules to which a carbohydrate has been attached

What are glycoproteins?

Proteins combines with carbohydrates

What are glyolipids?

Lipids bound to carbohydrates

What are polymers?

Large molecules made up of repeating units

What is a functional group?

Groups of atoms that tend to move from molecule to molecule as a single unit

What are covalent bonds?

The arrangement of electrons in the outer energy level (shell) of an atoms determines an element’s ability to bind w other elements

What is an ion?

An atom or molecule that gains or loses one or more electrons, it acquires an electrical charge and becomes an ion

What is an high-energy electron?

The electrons in certain atoms can capture energy from their environment and transfer it to other atoms

What is a double bond?

An adjacent atoms sharing two pairs of electrons rather than just one pair, it is represented by a double line (=)

What are polar molecules?

Molecules that develop regions of partial positive and negative charge when one or more atoms in the molecule have a strong attraction for electrons

What is a nonpolar molecule?

A molecule whose electrons are distributed so evenly that there are no regions of partial positive or negative charge

What is an ionic bond?

Known as electrostatic attractions, result from the attraction between ions with opposite charges

What is an anion?

Negatively charged ion, an atom that gains electrons

What is a cation?

Positively charged ion, an atom that gives up electrons

What is a hydrogen bond?

A weak attractive force between a hydrogen atom and a nearby oxygen, nitrogen, or fluorine atom.

What is surface tension?

The attractive force between water molecules that causes water to form spherical droplets when falling or to bead up when spilled onto a nonabsorbent surface

What are Van der Walls forces?

Weak, nonspecific attractions between the nucleus of any atom and the electrons of nearby atoms

What is solubility?

The degree to which a molecule is able to dissolve in a solvent, the more easily a molecule dissolves, the higher its solubility.

What is hydrophilic?

Molecules that are soluble in water

What is hydrophobic?

Molecules such as oils that do not dissolve well in water

What is primary structure?

The sequence of amino acids in the peptide chain

What is a secondary structure?

Spatial arrangement of amino acids in the chain

What is a tertiary structure?

It’s three-dimensional shape, create through spontaneous folding as the result of covalent bonds and non-covalent interactions.

What are globular proteins?

A mix of alpha-helices, beta-sheets, and amino acid chains that fold back on themselves

What are fibrous proteins?

Can be beta-strands or long chains of alpha-helices.

What is pH?

The concentration of free H+ in body fluids, or acidity.

What is an acid?

Molecule that ionizes and contributes an H+ to a solution

What is a buffer?

Any substance that moderates changes in pH

What is an enzyme?

Biological catalyst that speeds up chemical reaction.

What is a membrane transporter?

Proteins in cell membranes help move substances back and forth between the intracellular and extracellular compartments.

What are signal molecules?

Some proteins and smaller peptides act as hormones and other signal molecules

What are receptors?

Proteins that bind signal molecules and initiate cellular responses.

What are binding proteins?

Found mostly in the extracellular fluid, bind and transport molecules throughout the body

What are immunoglobulins?

Extracellular immune proteins, also called antibodies, that help protect the body from foreign invaders and substances.

What are regulatory proteins?

Regulatory proteins turn cell processes on and off or up and down

What is a binding site?

Region of an enzyme or transport protein to which the substrate binds.

What is a ligand?

Any molecule or ion that binds to another molecule

What is a substrate?

Ligands that bind to enzymes and membrane transporters.

What is a specificity?

The ability of a protein to bind to a certain ligand or group or related lignads

What is an induced-fit model?

The active site changes shape to fit either substrate or product molecules

What is affinity?

The degree to which a protein is attracted to a ligand

What is law of mass action?

For a reaction at equilibrium, the ratio of substrates to products is always the same.

What are agonists?

Molecules that combine with a receptor and mimic a response

What are isoforms?

Related forms of a molecule

What is a cofactor?

An inorganic or nonprotein organic molecule required for activation of protein

What are antagonists?

One substance opposes the action of another

What are competitive inhibitors?

Reversible antagonists that compete with the customary ligand for the binding site.

What is an allosteric modulator?

Binds to an enzyme away from the binding site and change the shape of the active site and by doing so change the shape of the binding site

What are covalent modulators?

Atoms or functional groups bind to proteins and affect their activity

What is up-regulation?

Increase in protein number or binding affinity that increases the response of the target cell

What is down-regulation?

Decrease in protein number or binding affinity that lessens response

What is saturation?

All active sites on a given amount of protein are filled with substrate and reaction rate is maximal