Cellular metabolism

anabolic = energy stored
catabolic = energy release to ATP

Catabolic
1. nutrient > CO2, H20
2. ADP + P > ATP

Cellular Respiration
1. anaerobic metabolism
2. aerobic metabolism

Reactions

1. thermodynamically favorable (release free energy)
2. thermodynamically unfavorable (require free energy)

covalent bonds are stable so molecules don't react spontaneously at phys conditions
activation energy excites stable ground state > reactive transition states
activation energy (not thermodynamics) determine reaction rate
so exergonic reactions don't occur due to high activation energy without assistance

enzyme = act as catalysts, lower activation energy
unaltered at end of reaction
act only on substrates (unlike inorganic catalysts)
only speed up 1 reaction of substrate (of many potential ones)
specificty = 3D #3 and #4 structure
enzyme has active site where substrate binds (conformation change)

enzyme and substrate have weak ionic or H bond
break via thermal motion
enzyme active site = R groups (polar nonpolar electrically charged)
so nonpolar substrate can't bind to polar/charged active site
coenzymes may be required for binding (nonproteinaceous, unchanged)

enzyme stabilize transition state substrate molecule
(lowers activation energy)
don't change reaction equilibria
increase reaction rate by bonding multiple reactants simultaneoulsy

enzymes are controlled
temperature, pH, substrate [], and
chemical agents:
1.competitive inhibitor -compete for enzyme active site, overcome by [substrate]
2.noncompetitive inhibitors - change enzyme not at active site
3.irreversible inhibitors - bond enzyme active site permanently

allosteric enzymes have active/inactive states
negative modulators stabilize inactive state

cooperativity - enzyme with 2+ identical binding sites where one bind increases 2nd site bind affinity

Organic compound

organic compounds:
1. carb
2. lipid
3. protein
4. nucleic acids

Carbs:
monosaccharides
3-6 C
C=O group in straight chain form
polysaccharides
6C monosaccharid chains
6C = hexoses e.g., glucose
polysacc = glycogen = 100s glucose

condensation= mono > polysacc
1 h20 is remove per 2 monosacc joined

hydrolysis = polysacc breakdown
1 h20 per 1 bond between 2 monosacc split

Lipids:
CHO
(may have P and N)
fat molecule = gylcerol + 3 fatty acids
glycerol (3C each with OH hydroxyl)
fatty acids = 4-24C chain with COOH
so fat = 3 fatty acids + glycerol via condensation
3fatty acids from hydrolysis of fat

Protein:
CHON (sometimes S)
H
R-C-COOH
NH2
20 aa common in proteins
each aa has the above C with amino and carboxyl group and side chain R
R makes aa unique
aa joined via condensation > peptide bonds
peptide bonds between COOH and NH2 of successive aa

1 aa = polypeptide
protein = 1+ polypeptides (each polypeptide = subunit)
multimeric= structure composed of several identical or different subunits held together by weak bonds
proteins stabilized by H bonds and covalent disulfide bonds
disulfide bond (S of 2 cysteine)
#1 linear sequence of aa
#2 spatial arrangement of nearby aa and locations of disulfide between subunits
motif = a-helix, b-sheet
#3 spatial arrangement of aa residues in polypeptide
#4 multimeric prot only have interactions between polypeptides

Nucleic Acid
1. deoxyribonucleic
2. ribonucleic acid
each have nucleotides
PN covalent bond to 5C sugar
DNA has 4 nucleotides (different nitrogenous base)
purine = adenine and guanine (2 rings)
pYrimidine = cYtosine thYmine (1 ring)
nucleotides bond at the P group and the deoxyribose
sequence of nucleotides = genetic info
DNA 2 nucleotide chains (oriented in opposite directions)
H bonds hold the bases together
double helix means only TA and GC
4 rungs = AT, TA, GC, CG

RNA
mRNA = DNA instructions transferred to cytoplasm for protein synth
rRNA = ribosomes, structural component of protein synth
tRNA = carry aa to ribosome for prot synth (according to mRA)

RNA has ribose, uracil not thymine, single stranded