Introduction and Cell Organization I Flashcards
homeostasis
property of a system that regulates internal environment and maintains a stable, constant condition of properties such as temperature or pH
allostasis
process of achieving homeostasis through physiological or behavioral change
glycogen
glucose polymer, storage form primarily in liver
Name the nonpolar, aliphatic amino acids.
glycine, alanine, proline, valine, leucine, isoleucine
Name the aromatic amino acids.
phenylalanine, tyrosine, and tryptophan
Name the polar, uncharged amino acids.
asparagine, glutamine, serine, threonine
Name the sulfur-containing amino acids.
methionine and cysteine
Name the charged amino aicds.
aspartate, glutamate, arginine, lysine, and histidine
alpha helix
Every four amino acids are on the same side of the helix, stabilized by intrachain hydrogen-bonding
beta sheets
more stretched out than an alpha helix, parallel or antiparallel strands
leucine zipper
two alpha helices, each leucine residue separated by four amino acids, all on the same side of the helix
helix-turn-helix
beta-alpha-beta
zinc finger
important for transcription
Name the four types of basic interactions that stabilize protein folds.
ionic bonds, hydrogen bonds, disulfide bonds, and van der Waals interactions
domains
continuous stretches of amino acids that are folded into tertiary structures independently of the rest of the protein, typically composed of several motifs
protein folds
conserved large patterns of three dimensional structures that have characteristic activities
actin fold
binds ATP, so many ATP binding proteins have similar folds
How many domains are shared among all proteins?
about 2000
protein “breathing”
the cumulation of many local small scale movements in secondary structure
protein family
proteins with similar amino acid sequences and three dimensional conformations, one or more protein domains in common
What are the major membrane lipids?
phospholipids, glycolipids, and cholesterol
Where do membrane lipids get synthesized?
endoplasmic reticulum
flippase
enzymes that flip phospholipids from one side of the membrane to the other
cholesterol
lipid in the membrane that increases fluidity
lipid rafts
areas of the membrane where there are aggregations of certain membrane lipids and have distinct physical properties
Describe the permeability of membranes.
Name the external forces and conditions that cells have to deal with.
mechanical forces - shear, compression, stretching, Brownian collisions
environmental conditions - temperature, osmotic/tonic, hydration, chemical
Describe the functions of plasma membmrane.
interaction with EC environment, cell movement, signaling, vesicular transport, anchoring of cytoskeleton
endoplasmic reticulum: smooth and rough ER
suynthesis and glycosylation of integral membrane proteins, secreted proteins, lysosomal enzymes
calcium storage
lipid synthesis
steroid synthesis
drug detoxification
surface for metabolism
golgi apparatus
glycosylation, sorting, and packaging of proteins and lipids for secretion or targeting to intracellular membranes and membrane enclosed compartments
lysosomes
digestion of macromolecules from phagocytosis, endocytosis, autophagy, and direct transfer using acid hydrolases
destructino of microbes
lysosomotropism of drugs
peroxisomes
oxidation of very long chain fatty acids
synthesis of plasmalogens
detox of phenos, formaldehyde, alcohols
mitochondria
TCA cycle, beta-oxidation, oxidative phosphorylation
urea cycle, apoptosis, signaling, differentiation, cell cycle, cell grwoth
calcium storage and signaling, intracellular lipid trafficking
heat production, heme synthesis, steroid synthesis
nucleus
chromosome maintenance
DNA replication/repair
RNA transcription and processing
nuclear envelope
control of nuclear-cytoplasmic traffic
regulation of chromatin activity
signaling from cytoplasm
shape and mechanical stability
outer membrane is continuous with the ER
