CHAPTER 2 AND 3 Flashcards
each orbital can hold a max of ____ electrons
2
isotopes
alternate forms of chemical elements with # NUMBER OF PROTONS but DIFFERENT # OF NEUTRONS
radioisotopes
isotopes that are unstable & will spontaneously emit energy/parts of nucleus via radiation
ionized groups
carboxyl, amino, phosphate
bond strength order
strongest = covalent
ionic
weakest = hydrogen
amphiphatic molecules
polarized region and nonpolar region
alkaline vs acidic solutions
alkaline = basic = >7
acidic = <7
carbohydrates
molecules contain carbon, hydrogen, oxygen
sugar monomers =
monosaccharides (ex: glucose)
2+ monosaccharides
disaccharides (ex: sucrose)
many monosaccharides
polysaccharides (ex: glycogen)
lipids
linked by nonpolar covalent bonds so low solubility in water
examples of lipids
1) steroids
2) phospholipids
3) triglycerides
4) fatty acids
fatty acids
provide energy for cellular metabolism
triglycerides
fats stored in adipose tissue that serve as energy reserve
phospholipids
3rd hydroxyl group is linked to a phosphate, amphipathic
steroids
cholesterol, cortisol, sex hormones
difference between DNA and RNA
DNA: store genetic info
RNA: decode info into instructions for linking together a specific sequence of amino acids
cytosol vs cytoplasm
cytoplasm is region outside of nucleus and cytosol is the fluid portion surrounding organelles
what two things have coordinated function to maintain fluidity
cholesterol and phospholipids
integral membrane proteins
amphipatic and can move laterally
(transmembrane proteins span the entire membrane)
peripheral membrane proteins
located at surface where they are bound to polar regions of IMP’s
integrins
ability of TMPs to organize cells into tissues and organs and bind to specific proteins in EC matrix + link them to membrane proteins
desosomes
accumulations of proteins known as “dense plaques” along cytoplasmic surface that provide structural integrity of tissues in the body
cadherins
proteins that extend from cell into EC space and bond to other cadherins
tight junctions
forms when the EC surfaces of 2 adjacent PMs join together so there is no space b/t them
gap junction
consists of protein channels linking the cytosols of adjacent cells (ex: muscle cells)
nucleus
storage + transmission of genetic information, contains nuclear pores and envelope
chromatin
threads formed by DNA, becomes chromosomes when coiled and condensed during cell division
ribsomes
protein factories
rough (granulated) ER
network of flattened sacs, proteins synthesized on the ribosomes enter the RER from which they are distributed to other organelles/secreted
smooth (ungranulated) ER
branched tubular network, contains enzymes for fatty acid + steroid synthesis, stores and releases Ca2+
golgi apparatus
flattened membrane sacs that concentrates, modifies, and sorts proteins arriving from RER via vesicles to other organelles
endosomes
of membrane-bound vesicular and tubular structures that lie b/t plasma membrane and GA
mitochondria
correlated with transfer of energy from chemical bonds to new ATP
lysosomes
contains digestive enzymes and break down bacteria and dead cell debris
peroxisomes
consume molecular oxygen to remove hydrogen from organic molecules
cytoskeleton
maintains and changes cell shape + produce cell movements
actin filament
monomers in cytoskeleton, comes from G-actin subunit
intermediate filament
twisted strands in cytoskeleton that contribute to cell shape + anchor nucleus, comes from several proteins
microtubules words
-comes from centrosome, surrounds centrioles
-cilia: hair-like extensions on cell surfaces with a central core of microtubules organized in a pattern similar to centrioles
microtubule filament
composed of TUBULIN and provides framework to maintain shape
transcription
mRNA synthesis
translation
protein synthesis
splisosomes
RNA splicing of INTRONS to allow for exons sequence to be continuous + splicing of the ends of the axons to form mRNA
protein assembly steps:
1) initiation: tRNA binds to small r-subunit –> initiation complex, then large subunit binds, enclosing mRNA between both subunits
elongation
protein is elongated by successive addition of amino acids
secretion of proteins:
1) mRNA binds to ribosmes
2) polypeptide chain enters lumen of RER
3) signal sequence is enzymatically removed from completed poly-peptide
4) protein is further modified in golgi apparatus
5) then packaged into a secretory vesicle that undergoes exocytosis
ubiquitin
proteins can be targeted for degradation by binding to peptide
ligand
any molecule/ion bound to a protein by
a) electrical attractions
b) weaker attractions
binds to BINDING SITES
allosteric modulation
when proteins have 2 binding sites, the non-covalent binding of a ligand to one site can alter the shape of the 2nd binding site
covalent modulation
covalent bonding of charged groups to some of protein’s side chains, therefore altering shape/activity of protein (ex: phosphorylation)
proteases
enzymes that are specialized to break proteins down into smaller polypeptides and amino acids (breaking down is PROTEOLYSIS)
proteins that are to be secreted or become integral membrane proteins contain a signal sequence in first 15-30 amino acids provide a ______
recognition signal
characteristics of enzymes
-undergoes no net chemical change
-specificity, affinity, competition, saturation
-can increase in both forward and reverse rates of a chemical reaction
-enzyme lowers activation energy of a reaction but doesn’t change net amount of energy added to reactants
glycolysis (cytosol)
breaks carbs into pyruvate or lactate
pyruvate oxidation (mitochondria)
converts pyruvate to acetyl coA
krebs cycle (mitochondrial membrane)
use acetyl coA to generate H-bearing enzymes like carbon dioxide and coenzymes to generate ATP in the electron transport chain
oxidative phosphorylation (mitochondria matrix)
uses oxygen and H-bearing enzymes to produce ATP
how much ATP does each cycle make?
glycolysis: technically 4, but 2 are consumed so 2 net ATP
PO: none
krebs cycle: 2 ATP
OP: 32-34
total: 36-38
cofactor
substance that binds to a specific site of enzyme that is necessary for enzyme’s activity
coenzyme
organic non-protein molecule that carries chemical groups between enzymes
glycogen —-> glucose 6-phosphate
glycogenolysis
glucose 6-phosphate —-> glycogen
glycogenesis
gluconeogenesis
formation of glucose in liver/kidneys from non-carb precursors
-pathway 1: from pyruvate –> oxaloacetate –> phosphoenolpyruvate
-pathway 2: glycerol enters pathway at level 4 and reverses
beta oxidation
a series of reactions with fatty acids which splits off a molecule of acetyl coA from the end of FA and transfers to pairs of H atoms to it.
oxidative deamination
removal of an amino group gives that results in ammonia and an oxygen atom derived from water to form a keto acid
transamination
removal of amino group by transferring amino group from amino acid to keto acid
