Chemical Basis for Life Flashcards
matter
anything that occupies space and has mass
mass
amount of matter a substance contains
weight
the force of gravity acting on an object with mass
volume
the amount of space an object takes up
the atom
consists of neutrons, protons, and electrons
atomic number
number of protons an atom has
mass number
total number of protons and neutrons
ions
any particle with a positive or a negative charge due to a gain or loss of electrons
cation
positively-charged ion
anion
negatively-charged ion
isotopes
different atoms of a single atom that has the same amount of protons but different amount of neutrons
ionic bond
created by the loss and gain of valence electrons from opposing charges which attract each other
covalent bond
caused when two or more atoms bond by sharing valence electrons; their is neither a loss or gain of electrons
non-polar covalent bond
when atoms in a covalent bond share electrons equally
polar covalent bond
when atoms in a covalent bond do not share electrons equally
hydrogen bond
when hydrogen forms a covalent bond with another atom, it will form a bond with other atoms that are also covalently bonded to hydrogen; no electrons are transferred from the atoms so it is not a true bond; this bond can form cohesion and adhesion
surface tension
results from formation of hydrogen bonds between the outermost layer of water molecules and the underlying molecules
capillarity
causes water to climb up the sides of a container due to the attraction between the (+) charge of water molecules and the (-) charge of the surface of the glass
synthetic reaction
occurs when two or more atoms combine to form a new and larger molecule
anabolism
the process of a synthetic reaction that occurs in the body
decomposition reaction
occurs when a chemical is broken down into small components
catabolism
the process of a decomposition reaction that occurs in the body
exchange reaction
combination of decomposition and synthetic reactions; The bond between A & B and between C & D breaks (decomposition.) New bonds are formed between A & D and between B & C (synthesis.)
AB + CD 🡪 AD + BC
solute
any substance that dissolves within another substance
solvent
any liquid that dissolves a solute
solution
the end product of a solute dissolved in a solvent
true solution
a homogeneous mixture of two or more substances in which substance dissolved (solute) in solvent has the particle size of less than 10-9 m or 1 nm; particles will not settle over time
colloid solution
a phase separated mixture in which one substance of microscopically dispersed insoluble or soluble particles is suspended throughout another substance; particles will not settle over time
suspension solution
a heterogeneous mixture in which the solid particles are spread throughout the liquid without dissolving in it; the particles in suspension are larger than the particles in a solution and will settle over time
ionization
when inorganic acids, bases, or salts are dissolved in water and they separate into ions
acid
dissociates into one or more hydrogen ions (H+); dissociates into one or more anions; proton donor
base
alkaline; dissociates into one or more hydroxide ions (OH-); dissociates into one or more cations; proton acceptor
salts
dissociates into both anions and cations; does not dissociate into hydrogen nor hydroxide ions; ionic salts are called electrolytes
pH scale
pH < 7 = acidic
pH > 7 = alkaline (basic)
pH = 7 = neutral
buffers
substances that maintain a neutral pH level; converts strong acids and bases into weak acids and bases
carbohydrates
includes sugars, starches, glycogen, and cellulose; can provide energy, structural support, and can become stored energy
monosaccharides
building blocks of carbohydrates; includes glucose, fructose, galactose, deoxyribose, and ribose
disaccharides
formed by combining two monosaccharides; loses a molecule of water during this process; includes sucrose and lactose
polysaccharides
formed by combining many monosaccharides; loses water by the same process that forms disaccharides; includes glycogen, starches, and cellulose
dehydration synthesis
bonds molecules together by removing water;
Glucose + Fructose 🡪 Sucrose + Water
hydrolysis
reverses dehydration synthesis by adding water which dissolves any bonds created;
Water + Sucrose 🡪 Glucose + Fructose
lipids
- used as energy by the body
- stored in fat tissue for future energy needs
- can act as a chemical messenger, insoluble in water
- typically hydrophobic
- four classes of lipids: neutral fats, phospholipids, steroids, eicosanoids
neutral fats
also called triglycerides, consists of a single glycerol and three fatty acid molecules
saturated fatty acids
have single-bonds between all hydrocarbon chains
unsaturated fatty acids
have one or more double-bonds between all hydrocarbon chains
phospholipids
- like triglycerides, phospholipids contain a glycerol backbone
- consists of a single glycerol, two fatty acid molecules, and a phosphate group
Phosphate group: Polar and hydrophilic, can interact with water
Fatty acid pair: Non-polar and hydrophobic, can only interact with other lipids
phospholipid bilayer
makes up cell membranes, prevents organelles from diffusing out of the cell as well as preventing unwanted substances from entering.
steroids
- contains four rings of carbon atoms
- non-polar and lipid-soluble
- cholesterol is a type of modified steroid (sterol) essential for the synthesis of bile salts and for providing structural support to cellular membranes
eicosanoids
- formed from a 20-carbon fatty acid called arachidonic acid
- consists of two principle subclasses: prostaglandins, leukotrienes
proteins
- Most abundant molecule in the body
- Provides much more functions than carbohydrates or lipids:
- Structural support (e.g. collagen, keratin)
- Regulatory support (e.g. insulin)
- Immunological (e.g. antibodies and interleukins)
- Transportation (e.g. hemoglobin)
- Catalytic (e.g. enzymes)
amino acids
- Amino acids: Essential building blocks of proteins.
- Contains an amino group, a carboxyl group, and a side chain, all attached to a single carbon atom.
- When proteins are synthesized, two amino acids form a covalent bond called a peptide bond. This pair of amino acids is called a dipeptide. Three amino acids form a tripeptide, four forms a tetrapeptide, and so on.
enzyme
- Conducts chemical reactions with very minimal energy usage.
- Enzymes are the body’s catalysts.
- The substance that an enzyme acts upon is called a substrate.
- Enzymes are highly specific and only works on specific substrates.
- lock-and-key mechanism
e.g. lipase, amylase, trypsin
nucleic acids
Consists of two classes:
- Deoxyribonucleic acids
- Ribonucleic acids
The building blocks of nucleic acids are nucleotides.
ATP
- Adenosine triphosphate is the ’energy currency’ of all living systems
- Stores energy and releases them upon breakdown (exergonic catabolic reaction)
- ATP functions:
- muscle contractions
- movement of chromosomes during cell division
- transporting and diffusing substances cross membranes
- synthesizing larger molecules from smaller ones
- etc.
