Cell Bio Final Exam

Prokaryotes vs eukaryotes

- Prokaryotes have no nucleus or membrane bound organelles

- Eukaryotes have a nucleus and membrane bound organelles

- Both can reproduce and have ribosomes

-prokaryotes are more diverse: archaea and bacteria

Aerobic vs anaerobic cells

aerobic uses oxygen, anaerobic does not require oxygen

Golgi apparatus

stacks of membranes called cisternae

things are shipped here and packaged and shipped to parts of cell or outside cell; cis faces nucleus trans faces cell membrane

peroxisomes

break down toxic metabolities and fatty acids, producing h2o2

nucleus

covered by nuclear enevelope and has nuclear pores; stores dna in chromosomes

mitochondria

generates usable energy from food (ATP)

rough er

contains 3 types of rna: rRNA tRNA mRNA

structure of flagella and cilia

9 (outer doublet microtubules) + 2 (central singlet microtubules). dynein helps cilia and flagella move

different types of intermediate filaments

3 cytosolic: keratin (epithelial: hair,nails, most diverse), vimentin (connective tissue, muscle, glial), neurofilaments (axons of nerve cells)

1 nuclear: nuclear lamins: supports nuclear envelope of all animal cells

dynamic instability

Rapid growth and shrinkage of microtubules.

when beta (pos) subunit has GTP it has affinity for more subunits, so it grows. when gdp bound, shrinks

Kinesins vs. Dyneins

Both are MOTOR PROTEINS with 2 globular heads (ATPase) and 1 tail

KINESINS: moves thing from (-) to (+)

DYNEINS:

moves thing from (+) to (-)

Muscle contraction

Myosin moves on actin which pulls actin filaments closer. No change in length of myosin or actin BUT sarcomeres length decreases

Cohesins vs condensins

Cohesins - link sister chromatids

Condensins - help condense chromosomes in prophase

Relationship between cdks and cyclin

cyclin is required for cdk-cyclin complex to be active/functional

allow cells to progress through cell cycle

ex. phosphorylated cdc25 phosphatase dephosphorylates/activates m-cdk/cyclin complex driving entry into mitosis

Atomic Mass vs Atomic Number

12=atomic mass (protons+neutrons); 6=atomic number (protons)

Acidic Amino Acids

aspartic acid, glutamic acid

Asp, Glu

D, E

Basic Amino acids

histidine, arginine, lysine

His, Arg, Lys

H, R, K

Noncovalent Interactions

hydrogen bonds, van der Waals forces, ionic interactions, electrostatic, dipole-dipole and hydrophobic interactions

Cell respiration equation

C6H12O6 + 6O2 >>>> 6H20 + 6CO2 +ATP (30)

Energetically favorable reactions

have a negative delta G; make more disorder; dissipate heat; only compare at STP

Catalysts/enzymes

speed up reactions by lowering activation energy; not consumed in reaction

myosin

with actin, helps with contraction

makes up contractile rings (with actin) for cytokinesis

attaches atp which detaches from actin. when adp and pi have been released back to normal conformation

condensation reaction

A reaction in which two molecules become covalently bonded to each other through the loss of water; also called dehydration reaction.

ex. synthesis of peptides, polysaccharides

molecular chaperones are

proteins that help other proteins fold

proteins with fibrous structure

collagen, elastin, keratin

actin, tubulin (microtubules)

Hydrolase

hydrolysis (addition of water)

Nuclease

break down nucleic acids by hydrolyzing bonds between nucleotides

Protease

enzyme that digests protein

Ligase

joining of molecules

Isomerase

catalyzes the rearrangement of bonds within a single molecule

Polymerase

catalyzes polymerization such as DNA or RNA synthesis

Kinase

adds phosphate

Phosphatase

removes phosphate

Oxidoreductase

catalyze oxidation-reduction reactions (trasnfer of e- or h+)

ATPase

hydrolyzes ATP to adp

Allosteric Binding/Inhibition

Molecule binds somewhere other than active site which changes its structure/function

Structure of Cell Membrane

Phospholipid bilayer; hydrophilic head, hydrophobic fatty acid tails.

Cholesterol decreases fluidity in membrane

Membrane proteins- transporters, ion channels, anchors, receptors, enzymes

Flippases

In Golgi membrane, cause some to go from lumen to cytosolic side. More specific (only for glycolipids, glycoproteins)

Scramblases

In ER membrane, randomly throws fatty acids from cytosolic to lumen side which allows for flip flop and makes a symmetrical bilayer

BRCA gene

Mutation in this gene increases the risk of ovarian and breast cancer

Spectrin

Cortex/fibrous protein that gives shape to an RBC plasma membrane

Transporters

require energy, such as Na+ Pump

Channels

allow ions and water to cross membrane

Pores

Porins (mitochondria and bacteria) allow small solutes in

Aquapores- allow water in

Valium

Binds GABA gated Cl- channels facilitating their opening. Inhibitory; tranquilizer

Action Potential

Starts when enough ligand gated Na+ channels. At threshold potential, Na+ voltage gated channels open (depolarization). Then Na+ VG channels close and K+ VG channels open (repolarization). Hyperpolarization if below the threshold potential

Ion gated channels

Allow ions to come in when certain neurotransmitters are bound

Inhibitory neurotransmitters

GABA and glycine (gated Cl- channels)

Excitatory neurotransmitters

acetylcholine and glutamate

Step 1 glycolysis: Glucose to

Glucose 6 phosphate; Enzyme: Hexokinase

Glucose 6 phosphate to

fructose-6-phosphate

phosphoglucose isomerase

fructose 6 phosphate to

fructose-1,6-bisphosphate

phosphofructokinase

fructose 1,6 bisphosphate to

dihydroxyacetone phosphate and glyceraldehyde 3-phosphate

Aldose

G3P to DHAP

triose phosphate isomerase

G3P to

1, 3 bisphosphoglycerate

G3P Dehydrogenase

NAD+ to NADH

1,3-bisphosphoglycerate to

3-phosphoglycerate

Phosphoglycerate Kinase

ADP to ATP

3 Phosphoglycerate to

2-phosphoglycerate

phosphoglycerate mutase

2-phosphoglcyerate to

phosphoenol pyruvate

enolase

phosphoenol pyruvate to

pyruvate

pyruvate kinase

ADP to ATP

Pyruvate to Acetyl CoA

pyruvate dehydrogenase

NAD+ to NADH

Acetyl CoA + Oxaloacetate

citrate

citrate synthase

citrate to

isocitrate

acontitase

isocitrate to

alpha-ketoglutarate

isocitrate dehydrogenase

NAD+ to NADH

alpha-ketoglutarate to

succinyl coa

a-keto dehydrogenase complex

NAD+ to NADH

succinyl coa to

succinate

succinyl coa synthetase

GDP to GTP

succinate to

fumarate

succinate dehydrogenase

FAD to FADH2

fumarate to

malate

fumerase

malate to

oxaloacetate

malate dehydrogenase

NAd+ to NADH

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain. ETC + Chemiosmosis

ETC pathway/complexes

NADH Dehydrogenase complex (NADH to NAD+) --> ubiquinone --> cytochrome c reductase complex --> cytochrome c --> cytochrome c oxidase complex (2 H+ + 1/2O2 to water)

Complexes pump H+ out

Nuclear localization signal

Allows proteins made in cytosol to be sent to nucleus

Binds to receptors known as nuclear import receptors which allow proteins to go through nuclear pore unchanged

Wnt signaling is related to

colorectal cancer

Trimeric subunits of G proteins

A subunit: when GDP bound inactive, when GTP bound active and disassociates

B subunit:

Cytoskeleton is made up of

Actin, microtubules, and intermediate filaments

G1 phase

growth, inactive cdks

S phase

S-CDk initiates DNA replication and prevents rereplication

Prophase

chromosomes condense and mitotic spindle forms

prometaphase

mitotic spindle breaks down

chromosomes attach to spindle microtubules via kinetochores

metaphase

Chromosomes line up in the equator of the cell

kinetochores attach to opposite poles of cell

Anaphase

sister chromatids separate and move to opposite poles

kinetochore microtubules get shorter AND spindle poles move apart

Telophase

nuclear envelope reassembles around each set of chromosomes

Cytokinesis

cytosol is divided into two by contractile ring made of actin and myosin

Function of centrioles

where spindle fibers organize, found in matrix of centrosome

Protein translocators

Binds signal sequences and allows protein to be threaded into organelle