1. Chemistry + Flashcards
1
Q
Properties of H2O
A
- great solvent.
- high heat capacity. must add a lot of energy to warm.
- Ice floats. H2O becomes less dense as it freezes.
- Cohesion/surface tension. attraction btw like subst. H bonding.
- Adhesion. attraction of unlike substances; capillary action: ability of liquid to flow w/o external forces (against gravity).
2
Q
Monosaccharids
A
- single sugar molec. (ex. glucose, fructose, galactose).
- alpha or beta based on position of OH on first anomeric C. (down = alpha, up= beta).
3
Q
Disaccharide
A
- two monosaccharides joined by glycosidic linkage (joined by dehydration).
- Sucrose = glucose + fructose
- lactose = glucose + galactose
- maltose = glucose + glucose
4
Q
Polysaccharide
A
- series of connected monosaccharides, polymer.
- bond via dehydration synthesis, breakdown via hydrolysis.
5
Q
Starch
A
- polymer of alpha glucose
- energy storage in plant cell
6
Q
Glycogen
A
- polymer of alpha glucose
- energy storage in animal cells
7
Q
Cellulose
A
- polymer of beta glucose
- plant cell walls
8
Q
Chitin
A
- polymer similar to cellulose but each beta glucose has a N-containing group attached to ring
- fungal cell walls (also exoskeleton of insects)
9
Q
Lipids
A
- hydrophobic molecules
- functions: insulation, energy storage, structural (cholesterol and phospholipids), endocrine
- triglycerides, phospholipids, steroids
10
Q
Triglycerides
A
- 3 fatty acid chains attached to a glycerol backbone
- saturated: no double bonds, bad for health, stack densely and form fat plaques
- unsaturated: double bonds, stack less dense
11
Q
Phospholipids
A
- two fatty acids and a phosphate group attached to a glycerol backbone
- amphipathic = both hydrophobic and hydrophilic
12
Q
Steroids
A
- three 6 membered rings and one 5 membered
- hormones and cholesterol (membrane component)
13
Q
Lipid Derivatives
A
- phospholipids
- waxes: esters of fatty acids and monohydroxylic alcohols
- steroids: sex hormones, cholesterol
14
Q
Carotenoids
A
- fatty acid carbon chains w/ conj double bonds and six membered C-rings at each end.
- pigment that produces colors in plants and animlas
15
Q
Porphyrins (tetrapyrroles)
A
- 4 joined pyrrole rings
- often complex w/ metal. (porphyrin heme complexes w/ Fe in hemoglobin, chlorophyll w/ Mg)
16
Q
Adipocytes
A
- specialized fat cells
- white fat cells: large lipid droplet, primarily triglycerides w/ small cytoplasm around it.
- brown fat cells: considerable cytoplasm, lipid droplet scattered throughout, and lots of mitochondria
17
Q
Glycolipids
A
- like phospholipids but w/ carb group instead of phos.
- note: lipids are insoluble so they are transported in blood via lipoproteins
18
Q
Lipids in membranes
A
- fluid
- in cold weather, to avoid rigidity, cells incorporate more mono and polyunsaturated fatty acids (lower m.p.)
19
Q
Proteins
A
- polymers of amino acids joined by peptide bonds
- storage, transport (hemoglobin carries O2, cytochromes carry e-), enzymes (amylase catalyzes breaking a-glycosidic bonds in starch
20
Q
Amino Acid Structure
A
- amino group, carboxylic acid group, and a variable side chain bonded to a central C
21
Q
Enzymes
A
- protein catalyst
- ex. amylase (catalyze breaking a-glycosidic bonds in starch.
- catalyzes both the forward and reverse rxns.
- cannot change spontaneity of a rxn.
- enzymes are almost always proteins, but sometimes RNA can act as an enzyme (riboenzyme)
22
Q
Cofactors
A
- nonportein molec. that assist enzymes
- holoenzyme is union of cofactor and enzyme
- enzyme is apoenzyme/apoprotein when not bound to cofactor
- organic -> coenzyme, ex. vitamins
- inorganic -> metal ions, Fe +2, Mg+2,
- prosthetic group -> cofactor strongly bound to enzyme
23
Q
Different Structures of a Protein
A
- primary: amino acid sequence
- secondary: 3d shape, H bonding btw amino and carboxyl groups, alpha helix, beta sheet
- tertiary: 3d due to noncovalent interactions, H bond, ionic, hydrophobic, disulfide bonds, van der walls.
- quaternary: grouping of two or more separate peptide chains.
24
Q
Three Protein Categories
A
- Globular: somewhat H2O soluble, many functions, enzymes, hormones, storage & transport, osmotic regulation, immune response, etc., mostly dominated by 3ary structure
- Fibrous/stuctural: not H2O soluble, long polymers, maintain strength of cellular and matrix structure, mostly dominated by 2ary structure.
- Membrane proteins: membrane pumps/channels/receptors
- Note: protein denaturation means 2ary structure onward is removed, not necessarily that the protein itself is broken down into amino acids.
25
Q
Nucleotide
A
- Nitrogen base, 5-C sugar, phosphate group
26
Q
Nucleoside
A
- Sugar + Base
27
Q
Purines
A
- Adenine and Guanine
- 2 rings
28
Q
Pyrimidines
A
- Thymine, Cytosine, Uracil
- 1 ring
29
Q
DNA
A
- polymer of nucleotides that contain deoxyribose
30
Q
RNA
A
- polymer of nucleotides that contain ribose, not deoxyribose
- Thymine replaced by uracil
- usually single stranded
31
Q
Cell Doctrine/Theory
A
- all living organisms are composed of one or more cells
- cell is the basic unit
- cells come from preexisting cells
- cells carry hereditary information
32
Q
RNA World Hypothesis
A
- self-replicating RNA molecules were precursors to current life
- RNA carries genetic info and can catalyze chemical reactions
- RNA is unstable compared to DNA, so more likely to participate in chemical rxns (due to extra OH group)
33
Q
Central Dogma of Genetics
A
DNA -> RNA -> Protein
34
Q
Stereomicroscope
A
- visible light for surface of sample
- can look at living samples, but low resolution
35
Q
Compound Microscope
A
- visible light for thin section of sample
- can look at some living samples (single cell layer),
- may require staining
36
Q
Phase Contrast
A
- uses light phases and contrast
- allows for detailed observation of living organisms
- good resolution/contrast but not good for thick samples
37
Q
Confocal laser scanning + fluorescence
A
- can look at thin slices while keeping sample intact
- can look at specific parts of cell via fluorescent tagging
- can look at living cells, but only fluorescently tagged parts
- used to observe mitosis
- can be used w/out fluorescence
38
Q
Scanning Electron Microscope
A
- look at surface of 3D objects w/ high resolution
- can’t use on living
39
Q
Transmission Electron Microscope
A
- look at thin cross-sections in high detail
- can look at internal structures
- very high resolution
- can’t be used on living things
40
Q
Electron Tomography
A
- 3D model buildup using TEM data
- can look at objects in 3D and see objects relative to one another
- can’t be used on living things
41
Q
Centrifugation
A
- spins + separates into layers based on density.
- most dense/fastest to pellet out the bottom is nuclei layer, spin faster -> mitochondria/chloroplasts/lysosomes. peroxisomes, spin faster -> microsomes/small vesicles, then ribosomes, viruses, larger macromolec
42
Q
Allosteric Enzyme
A
- both an active site for substrate binding and an allosteric site for activator/inhibitor
43
Q
Competitive Inhibition
A
- substance that mimics the substrate inhibits the enzyme by binding at active site
- can be overcome by increasing subs conc
- km raised, but Vmax is unchanged
44
Q
Noncompetetive Inhibition
A
- substance inhibits enzyme by binding elsewhere than active site
- substrate still binds but rxn is prevented from completing.
- km unchanged, Vmax is not
45
Q
Cooperativity
A
- enzyme more receptive to additional substrate binding after one substrate molecule attaches to active site.
- ex: hemoglobin binding to O2, although hemoglobin is not an enzyme
46
Q
Michaelis Constant (Km)
A
- substrate conc at which rate is 1/2 Vmax
- small Km indicates enzyme requires only small amount of substrate to become saturated
- raised Km = substrate binding worse
- lowered Km = substrate binding better
