Bio Molecules Flashcards
Globular proteins
1) spherical/ball shaped eg Hb, myoglobin
2) curl up = NON POLAR hydrophillic R groups point to center of mol AWAY from aqueous environment
3) POLAR hydrophilic R groups outside = mixing + dissociating in water easier
4) usually soluble
5) precise shape - have roles in metabolic activities, specific in nature
Secondary structure
- Primary structure coiled + FOLDING itself in specific way
- Fibrous
- Hydrophobic R groups point OUTWARDS
- Water insoluable
- H+ bonds between NH of 1 AA + CO of another AA
- Alpha helix and Beta pleated sheets
Polar molecules/bonds
1) have groups with dipoles
2) unequal sharing of e- between atoms, creating a partial +ve and partial -ve charge
2) attracted to H2O molecules as they also have dipoles = are hydrophilic and form H+ bonds
3) soluble in water
Eg- amino acids, glucose, NaC
How molecular structure of GLYCOGEN makes it suitable for storage (4)
- 1,4 and 1,6-α glycosidic bond
- ALPHA glucose = used for aerobic rep + releases energy
- lots of branches for enzyme attachment
2) can be hydrolyzed easily + quickly
3) compact + insoluble= no effect on water potential
Polysaccharides
A polymer whose subunits = monosaccharides joined via glycosidic bonds
• Eg- starch, glycogen, cellulose
• NOT sugars
• if glucose itself accumulated in cells it would dissolve + contents of the cell too concentrated = effects osmotic properties
• storage polysaccharides- convenient, compact, inert & insoluble
Define monomer and polymer
- many small molecules that combine to form a polymer (larger molecules).
- large molecules made from many similar repeating subunits e.g proteins/nucleic acids.
Define macromolecule and monosaccharides
- large molecules formed due to polymerization of monomers e.g proteins/polysaccharides.
- molecule consisting of a single sugar unit with general formula of C(H2O)n
Define isomer
- molecule w/ same chem formula + different structural arrangement
Breaking a glycosidic bond: disaccharide and polysaccharides e.g sucrose test
- hydrolysis - water is added into the ring
- disaccharide + polysaccharides broken down into hydrolysis reaction
-Sucrose heated w HCL used to break disaccharide = 2 monosaccharides when testing for non-reducing sugar (sucrose). = positive Benedict’s test
Molecule structure of starch (plant)
- made of 2 POLYMERS; Amylose and Amylopectin
- polymer of ALPHA glucose
- via condensation reactions between α-glucose linked by a 1-4 glycosidic links/bonds.
- MAIN storage polysaccharides PLANTS ONLY - inert,compact + insoluable (tightly coiled)
Structure of amylose(plant)
- made via condensation joined by 1,4 linked alpha glucose molecules (glycosidic bonds)
- long unbranching/NOT BRANCHED chain
-forms helix with 6 glucose molecules per turn and 300 per helix = COMPACT
Structure of amylopectin(plant)
- polymer of ALPHA glucose joined by 1,4 glycosidic bonds BUT branches of 1,6 glycosidic link bonds
-branched every 20 monomers = easier hydrolyzed for faster release of glucose monomers
Structure of cellulose
- MAIN structural of plant cell wall
- STRAIGHT UNBRANCHED PARELLEL chains
- subunit of BETA glucose
- insoluble + High mechanical strength (maintains turgidity/support)
- staggered ends
- many H+ within cellulose mol = forms microfibrils
- microfibrils held tgt by H+ = fibres
Why must polysaccharides be insoluable
- cannot dissolve in water as it affects water potential
- decreases water potential in OSMOSIS
- hydrolysis occurs
- cells burst if water enters (mammals)
Reducing sugars test- monosaccharides (simple sugars)
- add equal vol of Benedict’s reagent +food sample IN LIQUID FORM to test tube
- heat gently in boiling tube in WB AT 80ºC for 5 mins
- If RS present = blue,green, yellow, orange/brick red (HIGHEST)
- ^^^ conc of reducing sugars INCREASING
Test for non reducing sugar - sucrose P1
- 2cm^3 of sample to 2 cm^3 dilute HCL
- place in gently boiling water bath for 5 mins (hydrolyses disaccharide into 2 monosaccharides –> fructose + glucose)
- test with pH paper to check solution is alkaline
- Re-test solution w Benedict’s reagent
- Heat solution w 2cm3 of Benedict’s in gently boiling water bath for 5 mins
Starch/amylose test
- 2 cm^3 of sample in test tube,
- drops of iodine/potassium iodide SOLUTION to sample
- sample shaken/stirred
- if blue-black is QUICKLY produced = starch present
- iodine SOLUTION is yellow-brown
Proteins test in known liquid ALT TO BIURET
- mix equal vol of solution + dilute potassium hydroxide
- run dilute copper sulfate solution —-> solution
- LILAC ring @ interface = Protein
- blue to LILAC
Groups and their bonds
- AMINE (NH2)
- AA
- CARBS
- LIPIDS
Amine group = Proteins w polypeptide bonds
Amino acids= Peptide bonds
Carbohydrates= glycosidic bond
Lipids= Ester bond and Carboxyl groups (CH2 bonds + CH3 bonds) COCO
Why is it impt for alpha and beta glucose to differ?
- ISOMERS
- leads to greater chemical variety
- a- glucose is respiratory
- b- glucose is structured
SATURATED vs UNSATURATED
- saturated means molecules contain MAX num of H+ atoms (single bond)
- Unsaturated contaisn double bonds/ molecules contain fewer H+ atoms
- Unsaturated= lower MP than saturated
- Unsaturated fat —> forms oil/liquid
- Saturated fats= Solids
Uses of lipids
- insulation
- waterproofing
- energy store
- protection
- cell membrane structure
Lipid emulsion test
- take sample & add EQUAL vol of ethanol and EQUAL water vol
- SHAKE sample
- mix & if positive = white emulsion/suspension forms
- lipid present
- limitations= objective milk alr white/cloudy
Amino acids are amphoteric, meaning??
- molecules contain both acidic + basic groups
What is meant by tertiary protein structure
- PP chain/coiled —-> into globular ss
- IONIC BONDS = between IONIZED AMINE + IONIZED CARBXYL and +/- R groups
- H+ BONDS between NH AA + CO of another AA
- DISULPHIDE BRIDGES between sulfur in R groups of 2 cysteine AA
- HYDROPHOBIC interaction between R groups of 2 AA interior + HYDROPHILLIC R groups face exterior
- R groups attract/repel
Label each with their sugar group
- Ribose, glucose, maltose, starch, lactose, cellulose, glycogen
- Ribose= MONOSACCARIDE
- Glucose= MONOSACCHARIDE
- Maltose= DISACCHARIDE
- Starch= POLYSACCHARIDE
- Lactose= DISACCHARIDE
- Cellulose= POLYSACCHHARIDE
-Glycogen= POLYSACCHARIDE
STARCH v CELLULOSE
- Starch contains a-glucose VS Cellulose contains b- glucose
- Starch linked by a- glycosidic bonds VS Cellulose linked by b- glucose glycosidic bonds
- starch may contain branched chains VS cellulose unbranched chains
heating w X solution breaks glycosisidc bonds
- dilute HCL
GLYCOGEN VS COLLAGEN
G then C
- Carb vs protein
- A glucose vs AA
- Glycosidc ponds vs Peptide bond
- CHO vs CHON
MACROMOLS
Protein as a MACROMOL
Monomer: Amino acids
- Each AA has an amine group (-NH₂), a carboxyl group (-COOH), and a unique side chain (R-group).
- Role = enzymes, structural components, signaling, transport, etc.
- amphipathic (both hydrophilic and hydrophobic regions) because they contain polar and non-polar AA.
MacroMol
Carbs as Macromol
Monomer: Monosaccharides (e.g., glucose, fructose)
- Typically composed of CHO in a 1:2:1 ratio (e.g., C₆H₁₂O₆).
-Provide energy (e.g., glucose) and ss support (e.g., cellulose in plants
- hydrophilic because of many O-H groups, making them polar.
Marcomol
Lipids as a Macromol
Monomer: Glycerol and fatty acid
- Nonpolar or hydrophobic molecules, often containing long hydrocarbon chains.
- Energy storage, membrane structure, and signaling molecules (e.g., hormones).
- hydrophobic due to long hydrocarbon chains, though some, like phospholipids, have polar heads.
Macromol
Nucleic acids as Macromol
Monomer: Nucleotides (composed of a sugar, phosphate group, and nitrogenous base).
- DNA and RNA store and transmit genetic information.
- DNA serves as the blueprint for life, and RNA plays roles in protein synthesis and regulation.
- Hydrophilic because of the negatively charged phosphate groups.
List for each monomer which elements are present:
- AA
- Nucleotides
- Simple sugars
- Lipids/fatty acids
- CHON
- CHONP
- CHO
- CHO
why do nuclotides need phosohorus + why do AA need nitrogen
- Phosphorus is essential for the phosphodiester bonds that link nucleotides together in DNA and RNA.
- ## Amino Acids need nitrogen for the amine group (-NH₂).
Non polar mol/bonds
- Equal sharing of electrons, leading to no significant charge difference
- Hydrophobic: Repelled by water because they can’t form H+ bonds with water molecules.
