MCDB Unit 3

Ribosomes

Made of RNA and use mRNA processing to make primary sequence for proteins

Flagella

prokaryotes have motor at base that lets cell rotate while eukaryote cell whips

Mitochondria

cristae (folding in inner membrane for ATP production by burning sugars)

Nuclear envelope

network of tubules and sacs (cisternae)- also ER and Golgi for modify, fold, and sorting

Actin filaments

Cell shape by stiffening it

Cell division

muscle contraction

polymerize to push membrane forward (cell crawling)

Intermediate Filaments

structural support (nuclear lamina in inner membrane)

anchor chromosomes

secure around organelles to prevent drifting

slow dynamic so long term structural support

Microtubules

alpha + beta tubulin form flagella for cell movement

cell division

vesicles travel on them for intracellular movement

very dynamic/grow shrink and unstable

Surface area and volume

cristae (foldings) provide surface area in mitochondria

What is life?

take in resources and process with chemical reactions/breakdown and use proteins you make to reproduce

Oligosaccharides

glycans in cell recognition to identity cell as an address

Glycoproteins bond

Carbon attaches to O in OH of of threonine or serine amino acid or

N of NH2 for asparagine protein

crystalline gel phase

low temperature, long tails pack closely together- rigid and ordered

liquid ordered phase

tightly organized and packed but can move and stabilized by cholesterol

liquid crystal phase

high temperature, fluid and disordered, overlapping unsaturated tails

Diffusion

Spontaneous and increase entropy- need energy to organize

high concentration is high potential energy because incredibly organized and wants to reach equilibrium which increases entropy and potential energy is unleashed

Osmoregulation

Isotonic: equal water in and out

Hypertonic: solvent leaves as more solute outside

Hypotonic: solvent enters as more solute inside

Electrical Potential Gradient

difference in electrical charge causing movement by attraction forces

sodium potassium pump 3 NA out, 2 K in opposite gradient to create gradient while plants use proton pump of H out of cell- now secondary active transport as ATP not used and second pump is cotransporter

Glucose Cotransporter

too much glucose in blood so insulin bind to integral proteins that signal to pump glucose into cell and form glycogen to burn for sugar

Alpha helix

NH and CO backbone H bonding with side chains outside with polar side chain loop bond to water on outside to anchor protein

Integral membrane proteins functions

transport, receptor/signals, anchor membrane to cytoskeleton or nearby cells, id tags and attachment sites

single vs multi pass membrane proteins

single: cross once, receptor and anchor

multi: form pore connected by hydrophilic loops sticking out- split polar and nonpolar helix with alternating amino acids

Beta barrel proteins

ribbon pores with opposite directions to have hydrophilic inside and hydrophobic outside- rolled up sheet into cylinder

Lipid anchored proteins

covalently attached to lipid tail inside membrane to keep protein close to cell, cell signal/communication, bind to other integral proteins to keep close and stabilize

peripheral membrane proteins

noncovalent bond with integral for cell signaling and regulate membrane enzymes

Permeability

small nonpolar then small uncharged then large uncharged then ions

symport and antiport

symport: move molecules in same direction with same protein by using energy of one moving down electrical gradient to move another against

Carrier Proteins

bind and slightly change shape to close one end and open another- can be stopped with inhibitor

bind to 3 Na and get phosphate from ATP to change shape and take outside of cell (against gradient)

bind to 2 K outside and as phosphate falls/dephosphorylation, go back to OG shape and bring K inside also against gradient

symport bring Na back in with glucose also against gradient

Thermodynamic Laws

Energy transferred not created or destroyed

Transferring is not 100% efficient as released as heat and increase entropy

Types of energy

ability to do work- electrical: movement of electrical charges, thermal: kinetic energy of constant movement of molecules, potential: nonpolar has electrons far from positive nuclei so less stable and high potential energy, polar is stable as opposites attract and close to positive nuclei and lower potential energy

Types of chemical reactions

catabolism: breakdown molecules to release free energy, anabolism form large molecules and decrease entropy by using ATP

ATP

4 negative charges repel each other and close so high potential energy and easy to break bond between last two phosphate groups

Phosphorylation: add phosphate group where R groups repel it and change shape and increase in potential and free energy to drive reaction

can also change shape of motor proteins to make muscles contract or nerves send signals, push nonspontaneous reactions

Energy Coupling

couple exergonic energetically favorable reaction (breakdown of ATP) with unfavorable that is endergonic on the enzyme’s active site

Glycolysis

Reactants: one glucose, 2NAD+, 2 ADP and pi, cytoplasm

1. add phosphate to glucose now two G3P molecules

2. oxidize and NAD+ pick up proton

3. add phosphate groups to ATP and use substrate level phosphorylation with free floating phosphates to make 2 more ATP, now 2 pyruvates

Products: 2 pyruvates, 2 NADH + H, 4 ATP

Pyruvate Processing

Reactants: 2 pyruvate, 2 NAD+, one COA, matrix in inner membrane

1. remove carboxyl as CO2 so now two carbon

2. oxidize two carbon to make 2 NADH+ and now acetyl group

3. attach to coenzyme A to make acetyl Co-A

Products: acetyl Co-A, Co2, 2 NADH + H+

Citric Acid Cycle

Reactants: 2 acetyl, COA, 6 NAD+, 2 FAD+, 2 ADP and Pi in matrix

1. acetyl Co-A forms 6 carbon citric acid- remove two carbon for CO2 and oxidize to form 3 NADH + H+ and FADH2

2. energy used to remove is to attach phosphate to make ATP

3. regenerate 4 carbon and attach to acetyl and restart

Products: 2 CO2, 3 NADH + H+, 2FADH2, 2 ATP

ETC

Reactants: 10 NADH + H, 2 FADH2, O2, in cristae folding

1. drop off electrons and protein complexes change shape to move H+ against gradient into intermembrane space

2. ATP synthase takes protons to spin axle which changes F1 subunit shape to attach pi to ADP and make ATP (chemiosmosis)

3. Complex 4 where O2 takes electrons and protons to make H20

Products: H20, NAD+, FAD+, 32-34 ATP

Cystic Fibrosis Biology

Move Cl and now water also exits cell (high to low)- misfolded causing not to go to membrane so stuck in cell and can’t water down and thin lung lining causing thick mucus

transmembrane alpha helix phosphorylated by R domain (regulated)

Cystic Fibrosis affects

Lung sinuses infected

salty sweat

pancreas and liver intestines blocked

Cystic Fibrosis treatment

gene therapy, antibiotics, physical chest therapy, lung transplant, CFTR modulators to fix folding of CFTR protein