biological molecules💧 Flashcards
what happens in hydrolysis
water is added
how does salting preserve food
- reduces wp outside bacteria
- bacteria lose water by osmosis and cannot reproduce
why is mRNA smaller than DNA
- mRNA contains copy of one gene
- DNA contains many genes
differences between globular and fibrous proteins using hb and collagen
g- soluble
- hydrophilic R group on outside
- spherical
- forms h bonds with water
hb-haem group
-transports oxygen
f-insoluble, strong
- chains can form h bonds with adjacent chains
- structural role
- long chains
c-forms crosslinks between molecules
-connective tissue
r group interactions in tertiary structure
- positive or negative charge forms ionic bonds
- hydrophobic on inside
- hydrophilic on outside
- hydrogen bonds
- disulfide bonds between sulfur atoms
explain how these properties help organisms survive in a pond
- ice floats
- solvent
- lot of energy needed to break bonds
- molecules spread out
- lattice
- water below ice does not freeze
- organisms do not freeze and can move
- polar
- ions interact with water
- organisms uptake minerals
- high specific heat capacity
- hydrogen bonds
- lot of energy needed to break bonds
- temperature does not change much so enzymes can function
where are hydrogen bonds found in biological molecules
- water
- tertiary structure of protein
- a helix B pleated sheet
- between bases in DNA
cholesterol function
- energy storage
- regulates fluidity of membrane
- making vitamin D
why is glycogen good for storage
- compact
- high energy density
- easily broken down
- branched for enzymes to attach
- insoluble
function of glucose
- source of energy
- used for respiration
how is collagen similar to haemoglobin
- amino acid chains
- helix
- more than 1 polypeptide
- quaternary structure
describe structure of haemoglobin
-sequence of amino acids joined by peptide bonds
sec
- a helix
- hydrogen bonds
tert
- polypeptide undergoes further folding
- hydrophilic R group outside
- disulfide, ionic, hydrogen bonds
quat
- 4 polypeptides
- 2 alpha chains 2 beta chains
- 1 haem group per polypeptide
-prosthetic group haem contains Fe2+ ion
does cholesterol contain fatty acids
no lol
why can water form h bonds
-water molecule is polar as electrons are held closer to oxygen
what level of structure are alpha and beta sub units in
quaternary
why is waters solvent ability important
- medium for metabolic reactions
- organisms can take in minerals
- transport
- able to dilute toxic substances
describe collagen structure
- peptide bonds between amino acids
- left handed helix
- every third amino acid is glycine
- 3 polypeptide chains
- h bonds between polypeptide chains
- adjacent molecules joined by crosslinks
- crosslinks staggered
- fibril
properties of fibrous proteins
- insoluble
- strong
- unreactive
functions of fibrous proteins
protection, structure, elasticity, contraction
how to extract dna
- grind sample to break down cell walls
- salt helps DNA precipitate
- use detergent to break down nuclear envelope
- add protease to break down histones
- add cold ethanol to precipitate
how to calibrate colorimeter
set to zero absorbance using water
how to test for sucrose
- heat with benedicts (should be blue)
- boil with HCL then retest with benedicts (red)
structure difference between glycogen and amylopectin that makes glycogen a more suitable storage molecule
-glycogen more branched so can be broken down by enzymes faster
-branching gives more free ends where glucose can be added or removed
-glycogen more compact
-glycogen more coiled
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