Chemistry of Life

Chemistry

Holds the body together and drives reactions

Covalent bond

Nonmetals sharing pairs of electrons

Can be polar or nonpolar

Polar covalent bond

Electrons are shared unequally, meaning that 1 has a stronger pull than the other

Nonpolar covalent bond

Electrons are shared equally

Ionic bond

The complete transfer of electrons between a metal and a non-metal

Hydrogen bond

A weak attraction between a hydrogen atom covalently bonded to F, O, or N

Synthesis reaction

Smaller particles bonded together to form a larger, complex molecule

Example: Amino acids joining together to form a protein

Decomposition reaction

When bonds of a larger molecule is broken resulting in smaller, less complex molecules

Example: Glycogen breaking down to release glucose molecules

Exchange Reaction

When bonds are both broken and created

Example: AB + CD → AD + BC

Factors influencing the rate of chemical reactions

Temperature, concentration, and catalysts

Organic compounds

Chemical substances that contain C atoms covalently bonded to H atoms (C-H)

Examples: Carbs, lipids, proteins, nucleic acids, and ATP

Inorganic compounds

Compounds that do not contain C-H bonds

Examples: Water, minerals, salts, acids, and bases

Electrolytes

Substances that have an electrical charge when dissolved into a solution

pH

A solutions H+ concentration in comparison to OH-

Neutral pH

7

Acidic pH

Less than 7, meaning H+>OH-

Basic pH

Greater than 7, meaning H+<OH-

Plasma membrane

The semi permeable outer cell barrier

Cytoplasm

Intracellular fluid containing the cytoskeleton and organelles

Nucleus

The control center that contains DNA

Intracellular fluid

Fluid within cells

Interstitial fluid

Fluid within the surrounding cells, but not within the blood vessels

Extracellular fluid

Fluid outside of the cells

Plasma

The liquid part of blood

Cell junctions

Allow for additional means of communication and/or bind cells together

Tight junctions

A type of cell junction that is impermeable and forms a continuous seal around the cells to prevent molecules from passing though the intracellular space

Desmosomes

A type of cell junction that anchors and binds adjacent cells together. Acts like velcro

Gap junctions

A type of cell junction that allows for ions and small molecules to pass though and communicate

Random thermal motion

Kinetic energy that is affected by velocity, temp, and mass.

Smaller = faster

Diffusion

Movement of particles from one location to another because of random thermal motion, but is only effective over short distances

Divided into passive and facilitated

Diffusion equilibrium

The result, which is evenly distributed and moving

Net flux

Movement from high concentration to low concentration for non electrolytes

Passive diffusion

Over time solute molecules placed in a solvent will evenly distribute themselves WITHOUT using ATP

Includes simple diffusion

Simple diffusion

Fat soluble molecules directly pass though the phospholipid bilayer

Examples: O_² and CO_²

Phospholipid head

Hydrophilic and polar

Phospholipid tail

Hydrophobic and nonpolar

Facilitated diffusion

Diffusion down the concentration gradient requires something additional to pass through.

Includes carrier-mediated, channel-mediated, and osmosis

Carrier-mediated diffusion

Facilitated diffusion that requires a protein carrier to bind to a substrate and the transport protein to change shape

Channel-mediated diffusion

Facilitated diffusion of ions and other small molecules that requires a channel protein

Osmosis

Facilitated diffusion of a liquid (water) though an aquaporin to get through the lipid bilayer

Tonicity

How the solutions solute concentration affects cell volume though osmosis

Can be isotonic, hypertonic, or hypotonic

Hypertonic solution

Cells placed into hypertonic solutions lose water, which causes them to shrivel

Example: Salt water

Hypotonic solution

Cells placed into hypotonic solutions gain water, which causes them to swell, lyse, or burst

Example: Distilled water

Isotonic solution

Cells placed into isotonic solutions maintain normal shape, size, and function

Example: Saline or lactated ringers

Na+ electrolyte concentration

Inside cell concentration is lower than the outside, meaning the Na+ will flow into the cell

Ca₂+ electrolyte concentration

Inside the cell concentration is lower than the outside, meaning the Ca₂+ will flow into the cell

K+ electrolyte concentration

Inside the cell concentration is higher than the outside, meaning K+ will flow out of the cell

Leak channels

Always open

Chemical gradient

The difference in the concentration of a chemical substance across a membrane, meaning that ions move from high to low concentration

Electrical gradient

The difference in electrical charge across a membrane, meaning that ions are attracted to areas of opposite charge

Electrochemical gradient

The difference between the membrane potential and the equilibrium potential of an ion, which determines the passive diffusion of that ion through an open channel.

Active transport

Movement of solutes against their concentration gradient that requires ATP and a carrier protein

Can be primary or secondary

Primary active transport

Uses ATP to directly force ions against their concentration gradient

Example: Sodium Potassium pump

Secondary active transport

Rlies on the pre-existing electrochemical gradient created by primary transport to drive the movement

Endocytosis

When vesicles bring things into the cell, such as nutrients

Exocytosis

When vesicles secrete things out of the cell, such as waste

Transcytosis

A combo of endocytosis and exocytosis