U1 Lecture 2 Flashcards
- Covalent, Ionic, and Hydrogen Bonds - Cation and Anion - Chemical abbreviations - Calculate molar concentration - Define pH and buffer - List the 5 classes of organic compounds
Define atomic charge
- Protons are positive (+)
- Electrons are negative (-)
Define Ion
Particles with a net charge
- (+) cation
- (-) anion
Major elements in biology
O (65%), C (18%), H (10%), N (3%),
- P, Ca, Na, K, and Cl make up 4%
Define element
A substance that cannot be split into simpler substances by ordinary chemical means
Define molecule
Assembly of atoms held together by chemical bonds
Two types of chemical bonds
- Covalent bond
2. Ionic bond
Define covalent bonds
‘share’ electrons
Define ionic bonds
transfer of electrons between a metal and nonmetal that forms an anion or cation
Types of covlent bonds
Non-polar - ‘equal sharing
Polar - ‘unequal’ sharing
Hydrogen bonds
- Weak bond in biology
- Stabilize structures
Energy flow in reactions
- Breaking bonds requires energy
- Making bonds releases energy
Define metabolism
The result of cell manipulation of the energy stored in chemical bonds
Two types of energy
- Potential energy - the distance between particles
2. Kinetic energy - energy of motion
Define catalyst
Compounds that make reactions go faster by reducing the amount of energy required to get them started
ex: enzymes
Define solution
mixture of two or more components
Solutes and Solvents
Solutes are mixed in a solvent
Define aqueous solution
When the solvent is water
Polarity of water
Water is a polar molecule, therefore it can only bond to other polar molecules
Define concentration
Amount of compound divided by Unit of volume
moles/liter
1 mole =
6 x 10^23 particles
Avogadro’s number
Define pH
A number expressing the acidity or alkalinity of a solution on a logarithmic scale
- 7 is neutral
- Lower numbers are acidic and higher numbers are basic
- pH = -log [H+]
Define buffers
Systems that maintain the pH level in the body by donating or picking up H+ ions
“H+ sponge”
Define organic compounds
A molecule that contains carbon
Examples of Organic Compounds
- Lipid - C and H
- Carbohydrate - C, H and O
- Protein - C, H, O and N
- Nucleic Acid - C, H, O, N and P
Define lipid
A fatty acid with a polar head and non-polar tail
Define carbohydrate
Molecule with C, H and O
ex: glucose, fructose, sucrose, starches
Define protein
A large molecule consisting of 1+ amino acids
Define nucleic acids
A long nucleotide chain composed of phosphate groups connected to sugars and base pairs
High energy phosphates
- Adenosine triphosphate (ATP) = most powerful phosphate, composed of adenine (N group), ribose (O group) and 3 phosphate (P) groups
- Adenosine dihosphate (ADP) = Adenine, ribose, and 2 phosphate groups
