Cell Bio quiz 2

Atom

The basic unit of matter (protons + neutrons) surrounded by electrons orbiting in a shell

Atomic Number

The number of protons in an atom;

Electron Shell 1

Holds up to 2 elections (1 pair)

Electron shell 2

Holds up to 8 electrons (4 pairs)

Electron shell 3

Holds up to 8 electrons (4 pairs)

What is a Molecule

Two or more atoms joined together by chemical bonds

Covalent bond

sharing electrons between two nuclei Ex: H2O

Ionic Bond

transferring electrons from one atom to another

Example of ionic Bond

NaCI becomes Na+ and CI-

What is a Hydrogen bond

A weak attraction between a positive H atom and a negative O or N atom on a different molecule; holds water molecules together and holds the two strands of DNA together

What is a single bond

One shared pair of electrons between two atoms

What is a double bond

Stronger, shorter, more ridged, 2 shared paired of electrons

Polarity

An uneven distribution of electrons in a molecule, creating positive end and a partially negative

Polar molecule

A molecule with an unequal charge distribution ex: water polar molecules attract other polar molecules

Non-polar molecule

A molecule with equal charge distribution (O2) non-polar molecules attract other non-polar molecules

Hydrophilic

“Water loving”, describing polar molecules that dissolve easily in water ex: sugar

Hydrophobic

“Water-fearing”, describes non-polar molecules that don NOT dissolve in water ex: lipids/ats

Solute

The substance being dissolved in sugar water ex: sugar in sugar water

Solvent

The substance doing the dissolving ex: water in sugar water

Mole equation

A unit equal to 6×10²3 of something

Molecular weight

The weight of one mole of given molecule

Molarity (M) Formula

Molarity = moles of solute / liters of solution

Finding Moles from Grams

Moles = grams of substance / molecular weight (M.W.)

Ionization

The process by which a molecule splits into charged ions when dissolved in water (e.g. NaCl becomes Na+ and Cl-)

Acid

A solution where the concentration of H+ ions is greater than OH- ions ([H+] > [OH-])

Base (Alkaline)

A solution where the concentration of OH- ions is greater than H+ ions ([OH-] > [H+])

pH

A scale that measures how acidic or basic alkaline a solution is based on H+ and OH- ion concentration

Macromolecule

A large molecule found only in living organisms

Monomer

A single building-block molecule that links others to form a polymer

Polymer

A long chain of monomers joined together

Dimer

Two monomers joined together

Condensation

A reaction that joins two monomers together by removing one H and OH group; releases a water molecule

Hydrolysis

A reaction that splits a dimer/polymer apart by adding one H and one OH group back in; consumes a water molecule (ex: digestion)

Lipid (fat)

A macromolecule made of fatty acids and glycerol; used for energy reserve, membranes, and cell signaling

Fatty Acid

The subunit (monomer) that makes up lipids/fats

Phospholipid

A special type of lipid that makes up the cell membrane

Protein

A macromolecule made of amino acids folded into a functional 3D shape; used for structure

Amino acid

The subunit (monomer) of proteins, made of an amino group, a carboxyl group, a side chain, and a central carbon

Polypeptide

A long chain of amino acids linked together

Polysaccharide

A macromolecule made of long chains of sugar (monosaccharide) subunits, such as starch; a major energy storage molecule

Monosaccharide

A single sugar unit fructose) that is the subunit of polysaccharides

Nucleic Acid

A macromolecule (DNA or RNA) made of nucleotide subunits; encodes genetic information

Nucleotide

The subunit (monomer) of DNA and RNA

DNA Strand Bonding

hydrogen bonds

ATP (Adenosine Triphosphate)

The main energy carrier molecule in cells; stores energy in its phosphate bonds

Energy and Chemical Bonds

Building a chemical bond requires energy input; breaking a chemical bond releases energy

Elements of Life

Carbon (C), Oxygen (O), Hydrogen (H), and Nitrogen (N) make up about 96% of an organism's weight

Ultracentrifuge

A lab instrument used to separate macromolecules based on density/weight