Chapter 2 Flashcards
atomic number
of protons in an atom
mass number
protons + neutrons in an atom
atomic mass
average mass of all naturally occurring isotopes
free radicual
electrically charged atom/group of atoms with an unpaired electron in its outermost shell
metabolism
the sum of all the chemical reactions in the body
exergonic reaction
releases energy by breaking bond with more energy than bond formed
endergonic reaction
requires that energy be added to form a bond
Synthesis reactions
anabolism
A + B ➙ AB
Decomposition reactions
catabolism
AB ➙ A + B
Exchange reactions
AB + CD ➙ AD + CB
Reversible reactions
AC ↔ A + C
mixture
combo of elements/compounds that are physically blended together but are not bound by chemical bonds
colloid
differs from a solution mainly on basis of size of its particles (large enough to scatter light)
- insoluble microscopic dispersed phase suspended throughout another substance
- will not settle (or would take very long time)
suspension
heterogenous mixture containing solid particles large enough for sedimentation
- suspended material may mix with liquid or suspending medium for some time
Isomers
have same molecular formula but different structures
sucrose
glucose + fructose
lactose
glucose + galactose
Carbohydrates
provide most chemical energy needed for life
- 2:1 ratio of H to O
Lipids
contain C, H & O
few polar covalent bonds
hydrophobic
Lipoproteins
proteins + lipids
Fatty acids
carboxyl group & hydrocarbon chain
- simplest form of lipids
building blocks of triglycerides & phospholipids
Saturated FAs
single covalent bonds between C atoms which are saturated with H atoms
Unsaturated FAs
contain 1+ double covalent bonds between C atoms
Triglycerides
most plentiful lipids in body
- glycerol & 3 FAs attached by ester linkage
Phospholipids
important membrane components - amphipathic
- polar head (phosphate group), glycerol molecule & 2 non polar FA tails
Steroids
lipids molecules that have 4 rings of carbon atoms
- based on the lipid cholesterol molecule
types of steroids
sex hormones
bile salts
some vitamins
cholesterol
Nucleic acids
huge organic molecules composed of monomeric nucleotides
- contain C, H, O, N, P
- carry genetic info as DNA & RNA
- form molecules that contain our genetic code that regulates most activities that take place in our cells
Proteins
large molecules that contain C, H, O, N
made up of combos different amino acids
primary structure
give the unique sequence of AA
secondary structure
repeated twisting & folding
tertiary structure
3D shape
quaternary structure
arrangement of individual polypeptide chains in proteins containing more than 1
nucleotides
basic units of nucleic acids
- nitrogenous base, pentose sugar & phosphate
amino acid
C atom with H, carboxyl, amino & R group
RNA structure differs from DNA in (3) ways
1) single stranded
2) ribose instead of sugar deoxyribose
3) uracial replaces thymine
synthesis of ATP catalyzed by? What does it do?
ATP synthase
- adds terminal high E phosphate bond to ADP
hydrolysis of ATP catalyzed by?
ATPase
Enzymes
special protein that catalyze (speed up) metabolic reactions in all living cells
substrate
substance upon which enzymes has its effect
enzymes speed up chemical rxns by.. (3)
1) increasing frequency of collisions
2) lowering activation energy
3) properly orienting colliding molecules
Enzymes consist of (2) parts
1) apoenzyme - protein part
2) cofactor - non-protein part
conezymes vs cofactors
coenzyme - organic (contain carbon)
cofactor - metal ion
(3) important properties of enzymes
1) highly specific
2) highly efficient
3) subject to a variety of cellular controls
energy from 1 glucose is used during both anaerobic & aerobic respiration to create how many ATP?
36-38 ATP molecules
5 C sugars used in?
Nucleic acids
6 C sugars most easily recognized in?
Our diet
5 C sugars
Deoxyribose
Ribose
6 C sugars
Glucose
Fructose
Galactose
3 major groups of carbohydrates
Monosaccharides
Disaccharides
Polysaccharides
How are disaccharides formed?
By combining 2 monosaccharides by removing a water molecule (dehydration synthesis)
Principal polysaccharide in human body
Glycogen
When blood sugar levels drop…
Liver hydrolyzes glycogen to yield glucose which is released from liver into blood
Triglycerides produced through?
Reduced through?
Produced by dehydration synthesis
Reduced by hydrolysis
Energy in TAGs vs carbs & proteins
2x as much energy in TAGs
Antioxidant
Substances that inactivate oxygen-derived free radicals
Chemical bonds
Forces of attraction that hold together atoms of molecule
Chemical reactions occur when?
New bonds form and/or old bonds are broken
Inorganic compounds
Water, salts, acids, bases
Structurally simple
-Lack carbon
Organic compounds
Always contain carbon
Usually large, complex molecules
Dehydration synthesis
Reaction occurring when 2 small molecules combine to form 1 large molecule & water molecule
Hydrolysis
To loosen or break apart molecules with addition of water
Water has a high heat capacity
Can absorb/release relatively large amount of heat with only modest change in temp
- due to large # of H ions in water
Absorbed heat energy of water is used to?
Break hydrogen bonds resulting in less E used to speed up H2O molecules
Function of carbs
Provide chemical E needed for life
Converted to other substances which are used to build structures & generate ATP
- food reserve
LDL vs HDL
LDL - stick in arteries
HDL - carry cholesterol to liver
Dipeptides formed from?
2 as joined by covalent bond (peptide bond)
Polypeptide
Chain contains 10-2000 AAs
DNA
Remain inside nucleus
Master template of genetic code
RNA
Slightly different nucleic acid macromolecule that relays instructions from nucleus to guide assembly of AAs into proteins in cytoplasm
Law of Conservation of Energy
total mass of reactants = total mass of products
Energy
capacity to do work
What is transferred in a chemical reaction?
Energy
Kinetic Energy
energy of matter in motion
Potential Energy
due to? or?
energy stored in matter
- due to objects position in space OR stored in chemical bonds
Hydrogen Bonds
weak interactions between H & adjacent EN atoms
Hydrogen bonds result from?
attraction of oppositely charged part of molecules
In water, H bonding provides considerable ___ which creates very high ____ ___
cohesion
surface tension
Factors that cause collision (& chemical rxn to take place) include? (3)
1) temperature
2) [reactants]
3) presence/absence of catalyst
concentration
way of stating amount of molecule in solution
percent
relative mass of solute found in 100 ml solution
mole
convenient way of counting large #s of small things (atoms/molecules)
6.02 x 10^23
