ch.2 Flashcards
atom
the smallest stable unit of matter, composed of subatomic particles
protons
positively charged, found in the nucleus
electrons
negatively charged, found in shells
neutrons
neutral charge, found in the nucleus
isotope
element with same number of protons, different number of neutrons
mass number
the number of protons plus the number of neutrons
ionic bond
bonds created by the attractions between negative and positive ions
covalent bond
bonds created when atoms share electrons
cation
- electron donor
- loses electron
- positively charged
anion
- electron acceptor
- accepts electron
- negatively charged
non-polar covalent bond
equal sharing of electrons
polar covalent bond
unequal sharing of electrons
hydrogen bond
bond between hydrogen and an atom of oxygen, nitrogen or fluorine
decomposition reactions
break molecules into smaller fragments
synthesis reactions
assemble larger molecules from smaller molecules
exchange reactions
rearrange existing components of molecules into new products
reversible reactions
two reactions taking place at once
name the reaction:
AB -> A + B
decomposition
name the reaction:
A + B -> AB
synthesis
name the reaction:
AB + CD -> AD + CB
exchange
name the reaction:
A + B <-> AB
reversible
enzymes
catalysts that lower the activation energy of reactions and therefore speed up the reaction
inorganic compounds
do not contain carbon in bonds to hydrogen
organic compounds
- contain carbon in bonds to hydrogen
- ex. carbohydrates, proteins, lipids, and nucleic acids
4 properties of water
universal solvent, reactivity, high heat capacity, lubrication
water as a universal solvent
many molecules an compounds are water soluble
reactivity of water
in our body chemical reactions take place in water
high heat capacity of water
- remains liquid over a broad range of temperatures
- freezing and boiling temperatures are far apart
- carries a lot of heat when it evaporates
- changes temperature slowly
lubrication of water
water reduces friction between opposing surfaces
pH
the negative logarithm of the hydrogen ion concentration
acidic pH
- 0-7
- more H, less OH
basic pH
- 7-14
- more OH, less H
acids
- any solute that adds hydrogen ions to a solution
- proton donor
dissociation of strong acids and bases
dissociate completely in solution
bases
- any solute that removes hydrogen ions from a solution
- proton aceptor
dissociation of weak acids and bases
do not dissociate completely in solution
salt
an ionic compound that dissociates in water into cations and anions
buffers
- compounds that stabilize the p H of solutions
- can neutralize acids or bases and prevent fluctuations in pH
monomers
identical subunits that can join to form a polymer
polymers
a large molecule consisting of a long chain of monomer subunits
importance of amino group, NH2
- acts as a base
- accepting H+
- can form bonds with other molecules
importance of carboxyl group, COOH
- acts as an acid
- releases H+
importance of hydroxyl group, OH
may link molecules through dehydration synthesis
importance of phosphate group, PO4
may store energy in high-energy bonds
carbohydrates
- organic molecules that include C, H, and O
- most important energy source
monosaccharides
- simple sugars: glucose and fructose
- hydrophilic
disaccharides
- hydrophilic
- two monosaccharides joined together
- sucrose: table sugar
polysaccharides
- polymers of monosaccharides
- hydrophobic
- cellulose, starch, glycogen
lipids
- organic macromolecules which contain C and H
- structural components of cells and energy storage molecules
3 types of carbohydrates
- monosaccharides
- disaccharides
- polysaccharides
6 types of lipids
- fatty acids
- eicosanoids
- glycerides
- steroids
- phospholipds
- glycolipds
fatty acids
long chains of carbon and hydrogen with a carboxyl group (COOH) at one end
saturated fatty acids
have no double bonds in the hydrocarbon tail
unsaturated fatty acids
one or more double bonds in the hydrocarbon tail
eicosanoids
- lipids derived from the fatty acid arachidonic acid
- leukotrienes & prostaglandins
prostaglandins
used as chemicals for local communication in tissues (pain)
leukotrienes
active in the immune system in response to injury and disease
glycerides
consist of fatty acids attached to a glycerol molecule
types of glycerides
- monoglyceride
- diglyceride
- triglyceride
triglyceride functions
- energy source and energy reserve
- insulation to slow heat loss
- protection by cushioning vital organs
steroids
large lipid molecules that have a distinct four-ringed carbon structures (ex. cholesterol)
phospholipid
contain a diglyceride attached to a phosphate group and a nonlipid group
glycolipid
contain a diglyceride attached to a
carbohydrate
proteins
- organic macromolecules which contain C, H,
O, and N - most abundant and important organic molecules in the body
- monomer: amino acids
7 function of proteins
- support
- movement for muscle contraction and cells
- transport substances in blood and in cells
- buffering to prevent changes in pH
- metabolic regulation
- coordination
- immune defense
protein structure
- amino acids
- peptide bond links amino acids through dehydration synthesis
structure of amino acids
- amino group
- central carbon
- carboxyl group
- r group
primary protein structure
the specific sequence of amino acids in a polypeptide
secondary protein structure
the shape that results from hydrogen bonds that form between amino acids; may result in alpha helixes or beta-sheets
tertiary protein structure
coiling and folding due to interactions between the R groups that result in the protein’s final three-dimensional shape
quaternary protein structure
interaction between two or more polypeptide chains which results in a protein complex
globular proteins
- soluble in water
- shape is based on tertiary structure
fibrous proteins
- insoluble in water
- shape is based on secondary or quaternary
structures
nucleic acids
- large organic molecules composed of C,
H, O, N, and P - monomers: nucleotides
types of nucleic acids
- deoxyribonucleic acid (DNA)
- ribonucleic acid (RNA)
nucleotide structure
- phosphate group
- sugar
- nitrogenous base
purines vs pyrimidines
purines: adenine & guanine
pyrimidines: cytosine, thymine, uracil
DNA structure
- C binds to G
- A binds to T
- formed by hydrogen bonds
- pair of nucleotide strands
RNA structure
- C binds to G
- A binds to U
- single nucleotide chain
3 types of RNA
- messenger RNA (mRNA)
- transfer RNA (tRNA)
- ribosomal RNA (rRNA)
RNA function
protein synthesis
DNA function
stores genetic info
high-energy compounds
- derived from nucleotides
- contain covalent bonds
- breaking of bonds releases energy the cell can use
adenosine monophosphate (AMP)
organic substrate which consists of a nucleotide and one phosphate group
4 types of high-energy compounds
- adenosine monophosphate (AMP)
- adenosine diphosphate (ADP)
- adenosine triphosphate (ATP)
- adenosine triphosphatase (ATPase)
adenosine diphosphate (ADP)
a nucleotide with two phosphate groups
adenosine triphosphate (ATP)
- a nucleotide with three phosphate groups
- the most important high-energy compound and energy storage molecule in the body
adenosine triphosphatase (ATPase)
enzyme that catalyzes the break down of ATP to ADP
