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145 terms

Intro Biology

For the first test, Ch 1-7
STUDY
PLAY
4 types of large molecules in living things?
lipids*, proteins, carbohydrates, nucleic acids
Enzyme
specialized macromolecule that speed up chemical reaction in cell
Hydrolosis is
process of a polymer turning into a monomer
Carbohydrates are made of
sugars and their polymers
Function of the cytoskeleton
maintains the cell's shape/ structure
Structural Isomer
same # atoms, but arranged in different ways (ex. pentane and 2-methyl butane)
Geometric Isomer
same Carbon backbone, but with double bonds (=plainer, inflexible)(ex. cis/ trans isomers)
Enatiomers
Mirror images (= different biological sidegroups)
Polymer
repeated chain of monomers, use covalent bonds via condensation reaction (loss of H2O)
Polymers are made of
carbohydrates, proteins, and nucleic acids
monomer of carbohydrates
sugars
monomer of proteins
amino acids
monomer of nucleic acids
nucleotides
What 4 elements make up 96% of living matter?
C, H, O, N
Isotopes
differ in # of neurons
applied use of isotopes
date fossils, trace atoms through metabolic process, diagnose medical disorder
Electronegativity
How strongly atoms attract e- from other atoms
when does non-polar occur?
atoms share e- evenly
when does polar covalent occur?
1 atom is more electronegative
Weak bonds?
Ion and hydrogen bonds
cohesion
H2O sticks to self
adhesion
H2O sticks to surfaces
Specific heat
NRG needed to raise 1g of substance 1C
Heat
Kinetic NRG from molecular motion
monosaccharide
simple sugars (usually has CH2O), has carbonal group & multiple hydroxyl, sugars are aldose or ketose,
Disaccharide
2 monosaccharides with a glycosidic linkage (covalent bond via dehydration)
structural polysaccharide
ex. cellulose (microfibrils in plant cell walls), chitin (arthropod exoskeleton)
Why aren't lipids polymers?
hydrophobic, because of nonpolar C-H bonds in hydrocarbon chains
Hydrogenated
saturated
Phospholipids
hydrophilic head, hydrophobic tale, make cell membranes
Steroids
hormones and cholesterol; carbon skeleton with 4 rings
Where is cholesterol synthesized?
in the liver of vertebrates
polypeptide
polymer of amino acid
protein
1+ polypeptide
Denaturation
cell that lost its native shape (due to temp/ pH/ salt concentration)
where can you find DNA in a cell
nucleus & mitochondria
RNA
ribonucleic acid, controls protein synthesis
nucleotide
structural subunits of DNA and RNA; nitrogenous base (purine, pyramidine), pentose C, & phosphate group. Linked via sugars (sugar-phosphate-sugar-phosphate) to make nucleic acids
Purine
nitrogenous base for nucleotide; A, G
Pyramidine
nitrogenous base for nucleotide; C, T, U
Carbohydrates
made of sugar monomers, store NRG (starch=plants, glycogen=animals)
Disaccharide carbs
glucose, fructose, sucrose, lactose
fatty acids
glycerol + 3 hydrocarbon chains (tryglycerol)
saturated fats
solid at rT (butter, lard), no double bonds=saturated with hydrogen
unsaturated fats
liquid at rT (oils), have double bonds, lack flexibility, have a kink that restricts tessellation
amphipathic
describes a chemical compound that has both water loving, and water unloving properties
proteins
monomer: amino acids, many FXNs (structure, enzyme storage, transport, hormones, receptors, contractile proteins, motor, defensive)
chaperonins
make proteins fold in the correct way
nucleic acids
information stored and used, DNA(has t) & RNA(has u)
organelles
membrane-enclose compartments
cytology
study of cell structure
Biochemistry
study of molecules & chemical process of cells
cell fractionation
disassembles cells
ALL CELLS:
-bounded by plasma membrane
-cytosol semifluid suspension
-chromosomes (w/DNA) & ribosomes (make protein)
T/F
Eukaryotic cells house DNA in nucleus
TRUE
T/F
Eukaryotic cells are generally larger than prokaryotic
TRUE
Plasma membrane
barrier for 02/ nutrient/ waste passage
Magnification
object's image size: real size
Lysosome
in animals, digests macromolecules; helps cells renew itself
Nuclear envelope
double membrane of lipid bilayer; perforated by pore structure (pore complex), which regulates entry/ exit of proteins, RNA, & macromolecules
Nucleolus
non-membrane bound structure composed of proteins and nucleic acids found within the nucleus. Ribosomal RNA (rRNA) is transcribed and assembled within the nucleolus
Endomembrane system
nuclear envelope, ER, golgi apparatus, lysosomes, vacuoles, & plasma membrane
Smooth ER
synthesizes lipids, metabolizes carbs, detoxifies drug/ poisons, stores Ca+ ions
Chromosome
organized DNA, carries genetic info, made of chromatin (DNA & proteins)
food vacuoles
operate via phagocytosis
contractile vacuoles
pump H2O, maintain molecular/ ionic balance
mitochondria
FXN cellular respiration, generates ATP by extracting NRG from sugars, fats & fuels (w/ help of O2)
Chloroplast
organelle in plants where photosynthesis occurs; chlorophyl pigment; plastid w/ 3 membranes
peroxisome
"microbodies"; breaks down fatty acids; H2O2 byproduct
cristae
infoldings on mitochondria
cytoskeleton
polymer fibers through cytoplasm
-microtubules
-microfilaments
-intermediate filaments
microtubules
*thickest of cytoskeleton, made of tubulin, alpha or beta; FXN shape/ support "tracks"
microfilaments
actin monomer, very thin
intermediate filaments
keratin monomer, thick structure, w/ supercoiled fibers
centrosome
=pair of centrioles; structure in nucleus; made of tubilin
cilia
oar-like, many per cell
flagella
whip-like
Plant cell walls
outside plasma membrane, generally cellulose
Extracellular matrix
-connects to cytoskeleton
-change in ECM can signal changes in cell
-glycoprotein, collagens, proteoglycans
3 junctions between animal cells
-tight
-gap
-demosomes
Tight junction
so materials can diffuse between cells
Gap junction
like plasmodesmata; links cytoplasms
Demosomes
like rivets, keep cells together in sheets of tissue
Plasma membrane
has selective permeability (=LIFE)
Electron microscope
showed first cell membrane in 1950s
cholesterol
"temperature buffer" (liquid movement good; not melting or frozen stuck)
integral proteins
penetrate hydrophobic core of lipid bilayer; have 7 transmembrane helices (odd # = C & N terminus on opposite sides of membrane)
peripheral proteins
appendages to bilayer; attach to integral proteins
6 major fxns of proteins in lipid bilayer
-transport
-enzymatic activity
-signal transduction
-cell-cell recognition
-intercellular joining
-attachment to cytoskeleton/ extracellular matrix
Blood type
A, AB, B, O= variation in carbohydrates on surface of blood cells
membrane carbohydrates
glycoproteins & glycolipids
aquaporins
channel proteins, aid passage of H2O molecules
diffusion
movement down a concentration gradient (passive transport)
tonicity
ability of a solution to cause a cell to gain or lose H2O
isotonic
("same" tonicity) = no net movement across membrane
hypertonic
cell will lose H2O to its environment, shrivel, and die
hypotonic
cell will swell with H2O and burst
turgid
firm
flaccid
limp
plasmolysis
H2O loss in plants; plasma membrane separates from cell wall
transport protein
= facilitated diffusion; (channel & carrier proteins)
ion channels
gated channels that open/ close in response to stimulus
active transport
movement against gradient
Sodium-potassium pump
pumps Na out of plasma membrane and K into it. Main electrogenic pump in animals.
membrane potential
voltage across a membrane
electrochemical gradient
two forces that drive diffusion of ions across a membrane: chemical & electrical
Chemical force
ion's concentration gradient
Electrical force
effect of membrane potential on the ion's movement
electrogenic pump
transport protein that generates voltage across a membrane
proton pump
main electrogenic pump for plants
Cotransport
active transport driven by a concentration gradient
exocytosis
cell secrete certain molecules by fusing w/ plasma membrane
Endocytosis
phagocytosis, pinocytosis, receptor-mediated endocytosis
ligands
molecule binds specifically to receptor site of another molecule
Red blood cell
lipids (phospholipids) & proteins
nonpolar, hydrophobic
can diffuse through phospholipid bilayer
Rough ER (RER)
fxn: protein production, protein folding, quality control & dispatch. Rough because it has ribosomes on it.
Smooth ER (SER)
fxn: production and metabolism of fats and steroid hormones. Smooth because it has no ribosomes and is associated with slippery smooth fats
Archaea
domain of single celled microorganisms; have neither nucleus nor membrane bound organelles
Bacteria
large domain of prokaryotic microorganisms; lack true nucleus or organelles
Ribosome
a component of cells that synthesizes protein chains; assembles the twenty amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule.
Metabolism
Totality of an organism's chemical reactions; arises from interactions between molecules within the orderly environment of the cell
Metabolic Pathway
specific molecule which is altered in a number of defined steps, resulting in a certain product; each step catalyzed by a specific enzyme
Catabolic pathway
releases energy by breaking down complex molecules into simpler compounds (e.g. cellular respiration)
Anabolic pathway
("biosynthetic") consume energy to build complex molecules from simpler ones
Bioenergetics
the study of how energy flows through living organisms
Energy
the capacity to cause change; ability to do work
Kinetic energy
energy associated with the relative motion of objects
Heat "thermal" energy
kinetic energy associated with the random movement of atoms or molecules
Potential energy
energy that matter possesses because of its location or structure
Chemical energy
potential energy available for release in a chemical reaction
thermodynamics
the study of the energy transformations that occur in a collection of matter
First law of thermodynamics
Energy can be transferred and transformed, but it cannot be created or destroyed (principle of conservation of energy)
Entropy
a measure of disorder, or randomness
Second law of thermodynamics
Every energy transfer or transformation increases the entropy of the universe
Spontaneous
for a process to occur spontaneously, it must increase the entropy of the universe. Spontaneous rxns occur without the input of energy from the outside
Endergonic reaction
reaction that absorbs free energy from its surroundings (delta G is positive)
Energy coupling
the use of an exergonic process to drive an endergonic one
Exergonic reaction
proceeds with a net release of free energy; occur spontaneously
Signal transduction pathway
The process by which a signal on a cell's surface is converted to a specific cellular response
Biofilms
aggregations of bacteria that often form recognizable structures containing regions of specialized function
Paracrine signaling
Local signaling in animals in which numerous cells can simultaneously receive and respond to the molecules of growth factor produced by a signal cell in their vicinity
Synaptic signaling
Occurs in the nervous system when an electrical signal along a nerve cell triggers the secretion of a chemical signal carried by neurotransmitter molecules
unstable system
higher G
stable system
lower G