Unit 1.1 Biological compounds Flashcards
H2O, tell me about it’s charge?
Oxygen has small negative charge = 𝛿- (symbol called delta)
Hydrogen has small positive charge = 𝛿+
Due to H2O uneven distribution of charge, what is it?
A dipole
What are the bonds between oxygen and hydrogen in H2O called?
Covalent bond
What does it mean if it’s polar?
It’s hydrophilic
What does it mean if it’s non-polar?
It’s hydrophobic
What causes water molecules to stick together?
- Due to 𝛿+ & 𝛿-.
- Thus their attraction is called a hydrogen bond
- O from one H2O slight attracted to H from another H2O
How is water a metabolite?
Used in reactions such as:
Condensation - the forming of chemical bonds
Hydrolysis - the breaking of chemical bonds
What are all biochemical reactions in your bodies called?
Metabolism
Tell me about disulphide bonds?
- It appears s-s makes the whole chemical bond wavey or summin?
- Therefore removing them makes them straight as a line
- Also are strong covalent bonds formed by oxidation
Before getting started to all the nitty gritty load of information and content of this whole booklet, what’s the insight?
- Biological molecules
- Classed by main organic molecules which are:
1. Carbohydrates
2. Lipids
3. Proteins - In addition there are inorganic compounds near the ends of this so, yeah. Try link everything from the beginning, cuz that’s how everything flows in.
Explain the roles of glucose?
- Used as respiratory substrate
GO -> CWE?? - Used as building blocks for large molecules
e.g. Disaccharides
e.g. Sucrose
Glucose + Fructose
e.g. Polysaccharides
e.g. Starch, glycogen and cellulose
Glucose
Give me info of the 2 types of glucose
- Isomers of glucose
- Hexagon with C as base but first is actually O
- On 2nd C, OH at bottom, then should know rest
- 5th C, CH2OH
α - glucose (alpha)
On the right side of it: H up, OH down
β - glucose (beta)
On the right side of it: OH up, H down
How is glucose being small and soluble an advantage?
They can be easily carried around organisms and can move across cell membranes respectively
Tell me about the others types of monomers?
Fructose = C6H12O6
- Pentagon shaped
- O is first then u got C’s next, clockwise ofc
- Don’t think about α-glucose for the positions, just opposite ONLY AFTER C-2, however…
- … CH2OH is on top of C-2 & C-5 on the top (put on reverse for C-5)
Galactose = C6H12O6 still
- Hexagon shaped
- Think about α-glucose for the positions of such
- The only difference is the left side is the exact opposite on the right (HO up, H down)
Quite obscure but if u know u know
Tell me about the Main Organic Molecules
- Carbohydrates -> Carbon, Hydrogen and Oxygen
- Proteins -> CHO, Nitrogen
- Lipids -> Also like carbohydrates (CHO)
Last 2 = macromolecules
Tell me the 3 main categories of carbohydrates
Or ig they are monomer (only monosaccharides, perhaps polysaccharides are polymers?)
(huge)
Name:
1. Monosaccharide
2. Disaccharide
3. Polysaccharide
Meaning:
1. Single sugar
2. Double sugar
3. Multiple sugars
Examples:
1. Glucose
Fructose
Galactose
2. Maltose
Sucrose
Lactose
3. Starch
Glycogen
Cellulose
Chitin
Sub-Units:
1. N/A
2. Glucose + Glucose
Glucose + Fructose
Glucose + Galactose
3. Glucose for starch, glycogen & cellulose
Glucosamine for chitin
Found:
1. Widespread
Fruit
Milk
2. Germinating seeds
Fruit/Phloem
Milk
3. Plant storage - starch
Animal storage - glycogen
Plant cell wall - cellulose
Exoskeleton of insects - chitin
Properties:
1. & 2.
Sweet, white and soluble
3.
Not sweet, Not soluble
Tell me about the monosaccharides
C-Atoms:
- 3
- 5
- 6
Name:
1. Triose
2. Pentose
3. Hexose/Glucose
Molecular Formula:
1. C3H6O3
2. C5H10O5
3. C6H12O6
Notes:
1. Used in photosynthesis and respiration
2. Present in DNA and RNA
3. Respirations substrate (energy sources)
Tell me about disaccharides
General formula:
Monosaccharide + Monosaccharide –> Disaccharide + water
Example:
α - glucose + α - glucose –> Maltose + water
Visualize these glucoses (u should know how to draw them), then think about how they get together from each side (H-OH + H-OH) thus condensation reaction happens. And they are connected via H2O bond. Makes sense how H2O is produced.
- Above called a 1,4 glycosidic bond as carbon-1 and carbon-4 used in process of condensation
- All reactions are controlled by enzymes
If u happen to see this, go and draw the isomers of glucose and the other 2 monomers (fructose & galactose)
Sure
Tell me about polysaccharides
- Made from joining many monosaccharides in a polymerisation reaction, done by condensation.
So think about drawing disaccharides but it keeps going - They are storage compounds (starch and glycogen), are compact, inert and insoluble, and can be readily hydrolysed back to glucose quickly when needed for respiration
- Osmotically inactive
Tell me about glycogen
(polysaccharides)
- Found in animal cells storage
- Similar to amylopectin, made up of α - glucose molecules with 1,4 glycosidic bonds and branches where 1,6 glycosidic bonds are formed
- Glycogen even more branched than amylopectin
- Branches make it difficult to coil into a helix, so it has a more brush-like structure
Advantage of being shorter and so branched:
- Shorter: more compact for energy storage
- More branched: easily releases more readily hydrolysed glucose as more ends are available
- Glycogen molecules clump together to form granules in the muscle cells and the liver
- Glycogen can be easily broken down by an enzyme called glycogen phosphorylase
- Which is activated by hormone called glucagon when blood/glucose levels are low
What’s the advantage of a polysaccharide being shorter and so branched?
- Shorter: more compact for energy storage
- More branched: easily releases more readily hydrolysed glucose as more ends are available
List 3 ways in which the molecular structures of glycogen and amylose are similar?
- Both are polysaccharides
- Both are made of α-glucose
- Both have 1,4 glycosidic bonds
Tell me about starch (polysaccharides)
(Amylose)
- Not found in animal cell storage
- Found in chloroplasts in plant cells
- Consists of 2 components: amylose & amylopectin
- Amylose - made by many condensation reactions between α-glucose molecules with 1,4 glycosidic bonds
- Forms a long, unbranched chain that then coils up
- … because the chain is more compact, and easier to store
In terms of visualization:
- S’pose it’s easier to think that it’s wayyyy coiled up compared to glycogen
- I’m not too sure about how to visualize this but at least know the bonds between are hydrogen bonds for stability - well ofc, cuz it’s coiled up right? It’s gotta somehow be able to retain that coil or summin
- Amylose diagram = straight chain
Tell me about starch part 2 (polysaccharides)
(Amylopectin)
- Not found in animal cell storage
- Found in chloroplasts in plant cells
- Consists of 2 components: amylose & amylopectin
- Amylopectin - made by many 1,4 glycosidic bonds using α-glucose molecules
- But the chains are shorter than amylose, and branch out at the sides due to 1,6 glycosidic bonds
- Just like amylose, seems to hard to visualize. Tho I s’pose the key words are 1,4 & 1,6 glycosidic bonds yano?
- Okay so, 4 alpha glucoses together right? 1,4 glycosidic bonds
- But then that’s where the 1,6 glycosidic bond comes in, cuz that’s the one branch
- Think of it as fuckinnn neurons in ur brain lool
- Amylopectin diagram = straight chain with one branch
How do u test for starch?
- The use of iodine
- You can tell if it’s present when it goes from:
Brown –> blue/black - Trapped in amylose helice??? (I can’t read this sentence)
Tell me about cellulose
(polysaccharides)
- Structural role as it is mechanically strong
- Found in a plant cell wall
- Polymer of β-glucose joined by 1,4 glycosidic bond
In-depth visualization:
- Bunch of β-glucoses together but each one flipped by 180° using a 1,4 glycosidic bond
- Does that so that OH and OH can allow condensation
- β-glucose molecules are long and straight
- They lie parallel to each other
- Hydrogen bonds form along their length, so individual cellulose chains are bound together into strong microfibrils
Real visualization:
- A brick wall…
- Each row are cellulose fibers
- Each column are hydrogen bonds
Even more real visualization:
- It kinda looks like collagen (ofc no protein involved)
- Consisting of glucose chains which all together make it into a microfibril (or cellulose chain)
- Which then consisting of microfibrils which all together make it into macrofibril (or cellulose fiber)
- WHICH then consisting of macrofibrils which all together make it into cell wall
Cell wall:
- Cluster of macrofibrils
- Several fibres running in different directions, intertwined
- Advantage: strength
- Other substances in cell wall also help increase structural integrity as cellulose makes up 20% - 40% of the cell wall
- Cellulose can withstand high pressures due to osmosis ∴ pressure can have useful functions such as:
1. Support of plant tissues
2. Responsible for all expansion during growth - Cellulose fibres are fully permeable; can let everything in that’s small/soluble
Tell me about chitin
(polysaccharides)
- Found in insects
- Similar to cellulose but has amino acids added to form a mucopolysaccharide
- Has a structural role, but the monomer is glucosamine
- Chitin molecules are long, straight, parallel chains
- Occurs in the walls of fungi hyphae and in the exoskeleton of insects
Glucosamine monomer:
- Think of β-glucose but the bottom of C-2 atom, swaps OH with NHCOCH3
Glucosamine chain = microfibril:
- They can form straight chains from each glucosamine molecule flipping 180°
- Thus hydrogen bond forms between chains
- Thus achieves it’s strength
Tell me about lipids (●´⌓`●)
- Group of compounds that contains fats, oils and waxes
- Like carbohydrates, they contain Carbon, Hydrogen & Oxygen
- Lipids are insoluble in water, but soluble in certain organic solvents e.g. ethanol
- Hydrophobic
- Three types of lipids:
1. Triglycerides
2. Phospholipids
3. Cholesterol
Tell me about triglycerides
- Known as fats and oils
- Made from one glycerol molecule (C3H8O3 - alcohol)
- And three fatty acids molecules (- consists of a carboxyl group attached to a hydrocarbon tail)
(- The hydrocarbon tail is non-polar, making them insoluble in water) - Each fatty acid joins to the glycerol by a condensation reaction, which releases 3 water molecules
- Each fatty acid has a carboxyl group attached to their hydrocarbon tail
- That’s where it gets connected with glycerol via esterification
Visuals:
- U have one glycerol molecule on a side (C3H8O3 - alcohol), arranged in a column
- Then the other side u have 3 fatty acids arranged in each row with their COOH on their tail facing to each OH on the glycerol molecule
- Through condensation = gains +3 H2O and thus they are connected forming triglyceride (pH decrease = more acidic)
- Otherwise hydrolysis (well that’s if they are triglyceride first) = the loss of 3 H2O’s (pH increase = less acidic)
- In addition, they’re called ester bonds when glycerol and 3 fatty acids connect
Tell me about saturated and unsaturated triglycerides
Saturated fatty acid:
- Long ass chain (Think about a really long alkane)
- Last C atom - double bond with O and bond with OH
- Btw, high intake of these and u have cardiovascular disease (●´⌓`●)
(Poly)Unsaturated fatty acid:
- Still long ass chain but it’s in decline (stairs)
- Almost propane but C-3 as a double bond with the next almost propane
- The double bond are called ‘kinks’ (bends) “within chain”
- And just like above, last c atom - double bond with O and bond with OH
- Without poly = only one kink
Compare saturated fat and unsaturated fat
Saturated fat:
- Long hydrocarbon chain
- No double bonds present in chain
- No ‘kink’ present in chain
- Contains maximum n° of hydrogen atoms
- Mainly animal lipids
- Solid at room temperature
Unsaturated fat:
- Long hydrocarbon chain
- One/more double bonds present in chain
- ‘Kink’ present in chain
- Not fully saturated with hydrogen atoms
- Are plant lipids
- Liquid at room temperature
Explain monounsaturated fatty acid???
- Best of both worlds of saturated & unsaturated fatty acid?
- Ohhhh, so it’s like a saturated fatty acid but with 1 unsaturated carbon bond in the molecule
- ∴, just one ‘kink’
- Last C atom - double bond with O and bond with OH
Tell me the roles of triglycerides
High energy store:
- Lipids are non-polar
- ∴ insoluble in water e.g. seeds and animals
- Have a high proportion of hydrogen atoms relative to oxygen atoms
- ∴ yield more energy despite same mass w/ carbohydrates
Production of metabolic water:
- Some water is produced as a final result of respiration
- e.g. camel fat can be hydrolysed to release water
Thermal insulation:
- Fat conducts heat very slowly
- Having fat/blubber under skin keeps metabolic heat in
Waterproofing:
- In skin, waxy cuticles in leaves and insects are useful
- To prevent excess evaporation from the surface
Buoyancy:
- Lipids float on water
- Role = maintain buoyancy in animals
Source of vitamin D:
- Ye.
Protection:
- Protects organs from physical dmg in impacts/knocks e.g. kidneys
Tell me about phospholipids
- Similar to a triglyceride but
- One carboxyl group (COOH) replaced by a phosphate group
Visuals:
- I mean u remember the head with the lines = phospholipid simplified
- Phosphate group is polar = soluble (hydrophilic)
- The tails are non-polar = insoluble (hydrophobic)
- Phospholipids are said to be amphipathic because of its polar & non-polar nature
It’s major:
- Phospholipids are a major component of cell membranes
- In cells, the internal environment (the cytoplasm) is watery
- Outside cells, the external environment (tissue fluid bathing in cells) is watery
- Thus the arrange of phospholipids:
1. It’s just a row of them (only 2)
2. Head sides facing the other side (like it looks like a bad attempt of drawing teeth)
3. But ye in between, no water due to tails yano
4. But ye: drawing > phospholipids > cell membrane
(if you know u know)
Explain chemical structure of a phospholipid?
- Ah well, this seems complicated
- Phosphorus surrounded by oxygen with bottom being double bond (this is phosphate)
- On the right connected to a carbon that’s also connected to 2 hydrogens and a CH at the top
- With that CH connected with coo on the right and a H2C on the top
- Which is also connected to a coo on the right
(I feel like that’s the hydrophobic tails, next to the coo, the zig zags)
Compare triglycerides and phospholipids
Triglycerides:
- 3 fatty acids
- 3 ester bonds
- No phosphate, but glycerol
- No hydrophilic head
Phospholipids:
- 2 fatty acids
- 2 ester bonds
- 1 phosphate, no glycerol
- 1 hydrophilic bond
Tell me all about cholesterol ,’:)
- Small molecule made from 4 carbon based rings
- Not water soluble
- Found in food and made in liver from saturated fats
Roles:
- Found in cell membranes to regulate fluidity and strengthens the cell membrane
- Is used to make steroid hormones: testosterone, estrogen and vitamin D
- Makes bile, waterproof skin
Btw, too much cholesterol:
- Lines blood vessels causing atherosclerosis
- Which is the hardening or narrowing of arteries
- Ofc excess cholesterol linked to CVD
Now tell me about proteins
- Essential components of cell membranes
- Made up of amino acids (sub-units right there)
- Always contain CHON:
Carbon
Hydrogen
Oxygen
Nitrogen - And may also contain sulphur and/or phosphorus
Tell me about the 7 major classes of proteins
- Enzymes:
- Biological catalysts - Transport proteins:
- Haemoglobin carries oxygen - Defensive proteins:
- White blood cells attack and destroy invading microorganisms - Signal proteins:
- Carry messages around the body e.g.
- Hormone, insulin and glucagon controls blood sugar levels - Storage proteins:
- Albumen is the protein store that forms the white of eggs - Contractile proteins:
- Actin and myosin are proteins in muscles that enable them to contract - Structural proteins:
- Collagen
- Which adds strength to tendons, ligaments, bones and walls of arteries; keratin in hair and surface layers of skin
Explain chemical structure of amino acid?
- So u got a single C atom surrounded by
- NH2 on left (tangible <_<)
- H on top
- COOH on right (double bond with O, bond with OH)
- Rando ass atom on the bottom, that’s why it’s called R
Tell me the pH changes of amino acid
Well u know it’s neutral:
- Everything is the same, just like it’s NH2
More acidic:
- Molecule picks up H+ from solution
- Now it’s got NH3
Less acidic:
- Molecule releases H+ to solution
- Now it’s just NH
Amino acids are amphoteric and can act as buffers?
Tell me about that (define)
Amphoteric - both acidic and basic properties when they dissociate
Buffer - resists changes in pH when acid is added to them
- Useful in fair testing during experiments to keep pH constant
Tell me all about the joining of amino acids?
- Formation of dipeptide is a condensation reaction, resulting in a peptide bond
- The opposite is hydrolysis, the addition of water to break bonds
Visuals:
- 2 amino acids coming together huh?
- Well H2O is produced but for the connection:
- Forms a peptide bond (the C and the N connected)
- In addition, can say a dipeptide bond cuz if u look on the left:
N-C-C-N
,’:)
- Polypeptide - many amino acids bonded together
- Protein - one polypeptide chain or 2/more chains interacting together
Btw to break a peptide bond, you need an enzyme called protease
In cells, ribosome s are the sites where amino acids are linked to form polypeptides in enzymes controlled reactions. Where in a cell would you find ribosomes?
Rough Endoplasmic Reticulum and in the cytoplasm (free ribosomes)
Wth, linton work?
Tell me all about the structure of proteins?
Interesting analogy (what that mean?):
1° Primary - sequence of amino acids - Letters
2° Secondary - folding and coiling - Words
3° Tertiary - intertwines to itself; 3D - Sentences
4° Quaternary - association of polypeptide chains - Paragraph
Primary Structure - 1°:
- Determined by type, number and sequence of amino acids linked by peptide bonds
- The 20 amino acids give lots of possibilities for 1°
- Sequence is precise
Secondary Structure - 2°:
- Coil into α - helix (visualize a sad attempt of a spring - like u tryna draw it quick)
you can compare to amylose in terms of stability,
there are hydrogen bonds between peptide bonds in polypeptide chain
- Fold into β - pleated sheet (visualize: a zigzag.)
lol not amylopectin, but actually cellulose ig?
but it’s zigzags sooo, there’s ur difference
Tertiary Structure - 3°:
- Coils and pleats can fold onto themselves to form an overall 3D shape of the polypeptide chain
- Held by various bonds between the R - groups
- 3D shape is very precise; determines it function
- e.g. active site on enzyme
Visuals for 3°:
- Well now that’s where it gets complicated
- I get it when it means the R - groups, that’s the literal amino acid chains
- For the whole chain look, like, a Hershey’s kiss
- The top left consists of hydrogen bond OH…O
- The top top consists of hydrophobic bonds CH-C3H-C3H+CH3-CH3-CH (interactions)
- The middle middle consists of disulphide bond CH2-S-S-CH2 (bridge)
- The bottom middle consists of ionic bond CH2-NH3-O
Tell me about primary structure - 1° proteins
- Determined by type, number and sequence of amino acids linked by peptide bonds
- The 20 amino acids give lots of possibilities for 1°
- Sequence is precise
Tell me about secondary structure - 2° proteins
- Coil into α - helix (visualize a sad attempt of a spring - like u tryna draw it quick)
you can compare to amylose in terms of stability,
there are hydrogen bonds between peptide bonds in polypeptide chain - Fold into β - pleated sheet (visualize: a zigzag.)
lol not amylopectin, but actually cellulose ig?
but it’s zigzags sooo, there’s ur difference
Tell me about tertiary structure - 3° proteins
- Coils and pleats can fold onto themselves to form an overall 3D shape of the polypeptide chain
- Held by various bonds between the R - groups
- 3D shape is very precise; determines it function
- e.g. active site on enzyme
Explain the importance of the tertiary structure to the functioning enzyme
- Enzymes are proteins
- Tertiary structure determines 3D shape of enzyme
& shape of the active site - Active site has a specific shape and is complementary to a substrate
- Substrate can fit into an active site to form the enzyme substrate complex
If the active site is changed, then the enzyme is denatured and dysfunctional
Explain denaturation of protein?
- Bonds break but not peptide bonds
- The 3D specific structure is lost but the primary structure remains the same
O_o = links of amino acid
Explain the 2 ways of how a protein can be denatured?
Very high temperature:
- Protein molecule vibrates and bonds break; Protein loses its specific 3D structure (tertiary); process is irreversible
Very extreme pH:
- Hydrogen ions (H+) interact with the R groups of amino acids
- Affecting the way they bond with each other; specific 3D structure is lost
- If not too extreme however, process can be reversed
Tell me about graph of protein denaturation only with pH?
- Uhhhh, optimum pH is at the middle ig?
- That area can be reversible
- Otherwise, v. high/v. low = irreversible
Tell me about quaternary structure (- 4° - paragraph) of protein structure?
- Two or more polypeptide chains become held together, forming complex, biologically active molecules
- E.g. Globular (Spherical) protein “Haemoglobin”
Fibrous (Fibres) protein “Collagen”
Tell me allll about Haemoglobin - Hb
Visuals:
- Kinda like a large intestine distributed in 4 groups
- Consisting of 4 chains:
2 Alpha chains above
2 Beta chains below
- Has a haem group within each chain (a plus or summin?)
Explanation:
- Each chain is about 140 amino acids long
- Hb, a globular, soluble protein, consists of 4 polypeptide chains associated together
- Hydrophobic groups on the Hb molecule face inwards
- Hydrophilic groups of the Hb molecule face outwards
- Haem group contains iron ions (Fe2+)
- Haem group generally called prosthetic
- One oxygen molecule can combine with one haem group
- Hb can carry 8 oxygen atoms at once
4Fe2+ + 4O2 <-> FeO2
Hb + 4O2 <-> HbO8
<-> = reversible reaction
Tell me alll about collagen
- Similar to cellulose
- Found in skin, bones, tendons, blood vessel walls
- Structural, fibrous protein
- Strong and insoluble
Visuals:
- Just like cellulose type shi
Circle within circles with circle within helixs’
- Consisting of amino acid chains (or polypeptide chains) which all together form collagen molecules (triple helices)
- Which then collagen molecules all together form collagen fibrils
- WHICH THEN collagen fibrils all together form collagen fibers
- Collagen Fibers: interlinked by strong covalent bonds
In-depth visuals:
- Just what kyle said, different types of amino acids based on what the R is connected to that chemical structure ig
- A wave
- 1st = alanine (middle start)
2nd = glycine (mountain)
3rd = proline (bottom end)
- Repeats as a wave
- A collagen molecule consists of 3 polypeptide chains, each coiled in the shape of a loose helix
- These 3 helical polypeptide chains then wind tightly around each other to form a 3 stranded rope - a strong triple helix
- They can “super coil” like this because every third amino acid is the very small glycine (when R = H)
- They are held together by hydrogen bonds
- Each complete 3 stranded collagen molecule interacts with others lying parallel to it and make cross links forming fibrils and then fibres - interlinked by strong covalent bonds
- The end of the parallel molecules are staggered; this stops any weak spots across the fibres
- Hence collagen has great tensile strength
Additional visuals:
- Kinda reminds me of DNA code
- But ye each rows of diagonal alanine/glycine/proline
- Parallel to each other
Compare fibrous proteins & globular proteins
Fibrous proteins
Examples:
- Collagen
- Keratin (Hair)
- Silk (Spiders’ web)
Structure:
- Polypeptide chains parallel to each other
- Numerous cross-linkages to form long fibres
- Regular sequence of amino acids
- No hydrophilic groups on the outside
Properties:
- Stable/structural integrity
- Insoluble in water
- Metabolically inactive
Globular proteins
Examples:
- Enzymes
- Haemoglobin
- Antibodies
- Hormones
Structure:
- Spherical shape - very precise shape
- Irregular amino acid sequence
- Folded so hydrophilic groups are on the outside
- And hydrophobic groups on the inside
Properties:
- Relatively instable
- Soluble in water
- Metabolically active
Comparison of collagen to haemoglobin?
Collagen:
- Fibrous protein
- Insoluble
- Primary structure - made up of 3 amino acids only
- No prosthetic group
- 3 polypeptide chains
- Structural function
Haemoglobin:
- Globular protein
- Soluble
- Primary structure - made of many amino acids
- Prosthetic haem group
- 4 polypeptide chains (2 α-chains & β-chains)
- Transport function
What are the similarities of collagen and haemoglobin?
Both have:
- Amino acid chains with peptide bonds
- A helix structure
- Tertiary structures that are hydrogen, disulphide bonds and ionic bonds
(H, S-S)
- A quaternary structure
- More than one polypeptide chain
Tell me all about the inorganic ions
Ion:
1. Magnesium
2. Iron
3. Calcium
4. Phosphate
Formula:
1. Mg2+
2. Fe2+
3. Ca2+
4. P(O4)3- (should know what that is written like)
Functions:
1. Essential for photosynthesis in plants
- Magnesium aids chloroplasts to capture sun energy
- Muscles use magnesium to contract and relax
2. Is a constituent of haemoglobin, which transports oxygen in red blood cells - erythrocytes)
- Essential in production of chlorophyll, gather of oxygen and transport of oxygen
- Essential for cognitive function - memory, problem-solving, concentration and learning
3. Crucial component of bones and teeth in mammals; structural integrity
- Crucial component of plant cell walls; structural integrity
- Helps blood clotting, blood vessel and muscle contractions, enzyme and hormone secretion and CNS functioning
- Works well when mixed? with PO4 (phosphate)
4. Used for making nucleotides, including ATP, and are a constituent of phospholipids
- Found in biological membranes and plasma
- Plants can resist diseases because of phosphorus and how it develops the plant quickly
- Vital for DNA (sugar-phosphate backbone)
Tell me all about the food tests
Carbohydrates
Reducing Sugar - Glucose, Galactose, Maltose, Fructose:
- Known as they reduce the blue Cu2+ in the copper sulphate present in benedict’s reagent to orange Cu+ of copper oxide on heating
1. Put 2cm depth of Benedicts’ into a test tube and add sample of reducing sugar
2. Heat in a thermostatically controlled water bath at 80°C for 5 minutes
3. Colour change - Blue to orange if positive
Non-reducing Sugar - Sucrose:
- Sucrose gives a negative test with Benedict so it must be hydrolysed into its monosaccharide (glucose + fructose)
1. Add sample into boiling tube and add 2cm depth of HCl
2. Heat gently in a bunsen flame
3. Allow to cool then add NaOH/NaHCO3 to neutralise into pH 7
4. Then just use test of reducing sugar
Starch:
1. Place 2cm depth of starch suspension in a test tube
2. Add a few drops of iodine solution (iodine in potassium iodide)
3. Positive color change = Brown to Blue/Black
Protein:
- Amine groups in protein molecules react with the copper ions in Biuret to form lilac colour
1. Add 2cm of egg albumen (pure protein) into test tube
2. Add 1cm depth of Biuret
3. Positive colour change = Blue to Lilac
Lipid:
- Insoluble in liquid, soluble in alcohol
- Called an emulsion test
1. Add 1cm of oil in test tube
2. Add 2cm of ethanol to the test tube
3. Shake vigorously to break ester bonds
4. Add water into test tube
Sweet, ofc, questions later, but other than that, understand from first principles
Let’s go
