1. Chemistry + Flashcards
(46 cards)
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
Nucleotide
- Nitrogen base, 5-C sugar, phosphate group
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Nucleoside
- Sugar + Base
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Purines
- Adenine and Guanine
| - 2 rings
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Pyrimidines
- Thymine, Cytosine, Uracil
| - 1 ring
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DNA
- polymer of nucleotides that contain deoxyribose
30
RNA
- polymer of nucleotides that contain ribose, not deoxyribose
- Thymine replaced by uracil
- usually single stranded
31
Cell Doctrine/Theory
1. all living organisms are composed of one or more cells
2. cell is the basic unit
3. cells come from preexisting cells
4. cells carry hereditary information
32
RNA World Hypothesis
- 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
Central Dogma of Genetics
DNA -> RNA -> Protein
34
Stereomicroscope
- visible light for surface of sample
| - can look at living samples, but low resolution
35
Compound Microscope
- visible light for thin section of sample
- can look at some living samples (single cell layer),
- may require staining
36
Phase Contrast
- uses light phases and contrast
- allows for detailed observation of living organisms
- good resolution/contrast but not good for thick samples
37
Confocal laser scanning + fluorescence
- 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
Scanning Electron Microscope
- look at surface of 3D objects w/ high resolution
| - can't use on living
39
Transmission Electron Microscope
- look at thin cross-sections in high detail
- can look at internal structures
- very high resolution
- can't be used on living things
40
Electron Tomography
- 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
Centrifugation
- 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
Allosteric Enzyme
- both an active site for substrate binding and an allosteric site for activator/inhibitor
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Competitive Inhibition
- 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
Noncompetetive Inhibition
- substance inhibits enzyme by binding elsewhere than active site
- substrate still binds but rxn is prevented from completing.
- km unchanged, Vmax is not
45
Cooperativity
- 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
Michaelis Constant (Km)
- 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
