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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
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