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What are the 3 most common monosaccharides?
glucose, fructose, galactose
What is the difference between alpha and beta glucose?
in alpha glucose, the hydrogen is on top in the first carbon group
What is the difference between alpha glucose and galactose?
in carbon group 4, the hydrogen in galactose is on the bottom
What is a condensation reaction (between saccharides)?
water is removed to form a glycosidic bond between 2 monosaccharides
What is a hydrolysis reaction (between saccharides)?
water is added to split disaccharides into monosaccharides
What monosaccharides make up maltose?
alpha glucose + alpha glucose
What monosaccharides make up sucrose?
alpha glucose + fructose
What monosaccharides make up lactose?
alpha glucose and beta galactose
What are polysaccharides?
polymers formed by joining together many monosaccharide molecules
What are 3 properties of polysaccharides?
large, insoluble, suitable for storage or structural support
What monosaccharides make up starch?
alpha glucose
What bonds are in starch?
glycosidic bonds formed by condensation reactions
Where is starch found?
in plants in the form of small grains
What kind of chains does starch have?
branched or unbranched
What kind of chains does amylopectin have?
branched
What kind of chains does amylose have?
unbranched
What type of glycosidic bonds are in amylose?
1,4
What type of glycosidic bonds are in amylopectin?
1,4 and 1,6
What are the benefits of starch being insoluble?
so it doesn’t affect water potential as water is not drawn into cells by osmosis
Why is starch compact?
it is branched and coiled so can store many molecules in a small area
What happens when starch is hydrolysed?
alpha glucose is provided for respiration
Starch is easily broken down by enzymes because of…?
more ends and branched
Why is starch large?
so can’t cross cell membrane
What monosaccharides make up glycogen?
alpha glucose
What bonds does glycogen have?
1,4 and 1,6 glycosidic bonds
Where is glycogen found?
in animals and bacteria
Glycogen is ______ branched
highly
How does glycogen store carbohydrates?
in small granules
What are 3 features of glycogen?
insoluble, compact, more highly branched
What monosaccharides make up cellulose?
beta glucose
What bonds does cellulose have?
1,4 glycosidic bonds formed by condensation reactions
What is the structure of cellulose?
straight, unbranched chains that run parallel to one another
What bonds form as cross-linkages between adjacent chains of cellulose?
hydrogen bonds
What are the cross-linkages/hydrogen bonds called?
microfibrils
What do the cross-linkages/hydrogen bonds do?
strengthen cellulose
Where is cellulose found?
cell walls of plant cells
How many carbon atoms do pentose monosaccharides contain?
5
What are two examples of pentose molecules?
ribose and deoxyribose
What is the test for reducing sugars?
add benedict’s reagent to the sample and heat in a water bath
What is the positive test for reducing sugars?
blue to brick red
What is the test for starch?
add iodine solution to food sample in test tube
What is the positive test for starch?
yellow to blue/black
How do you hydrolyse a non-reducing sugar?
add hydrochloric acid to food sample
What do you do after hydrolysing a non-reducing sugar?
place test tube in water bath
How do you neutralise the hydrochloric acid?
add sodium hydrogencarbonate solution and test with pH paper is alkaline
What do you do after neutralising the hydrochloric acid?
retest using test for reducing sugars
What elements do lipids contain?
C, H, O
What bonds do lipids contain?
ester bonds
Are lipids soluble in water?
no
What are lipids soluble in?
organic solvents like alcohols
What are the two main groups of lipids?
triglycerides and phospholipids
What are the 4 main roles of lipids?
source of energy, waterproofing, insulation, protection
What is the structure of triglycerides?
3 fatty acids combined with glycerol
What joins the fatty acids and glycerol?
ester bonds
What is the difference between saturated and unsaturated lipids?
unsaturated chain has at least one carbon-carbon double bond
What is the structure of phospholipids?
two fatty acids combined with glycerol and a phosphate molecule
Fatty acid molecules in phospholipids are…?
hydrophobic
Phosphate molecules in phospholipids are…?
hydrophilic
Phospholipids are ____ molecules
polar
What is formed in the presence of phospholipids in an aqueous environment?
bilayer within cell-surface membranes
What are glycolipids?
combining carbohydrates within the cell-surface membrane with phospholipids
What is the emulsion test for lipids?
add ethanol and water and shake gently
What is a positive test for lipids?
cloudy white emulsion
What bonds are in a polypeptide chain?
peptide bonds
How are peptide bonds formed?
through a condensation reaction between the carbon atom of one amino acid and the nitrogen atom of another amino acid
What is the primary structure of proteins?
the sequence of amino acids in the polypeptide chain
What bonds are in the primary structure?
peptide bonds
What does the primary structure determine?
the shape and function of the protein
What bonds are in the secondary structure of proteins?
weak hydrogen bonds
What are the two types of secondary structures?
alpha helix and beta pleated sheet
What is the tertiary structure?
more complex, 3D structure
What bonds are in the tertiary structure?
peptide, hydrogen, ionic, and disulfide bonds
What is the quaternary structure?
large, complex molecule
What are the types of quaternary structures?
fibrous (structural) or globular (functional)
What are prosthetic groups in quaternary structures?
non-protein groups associated with the molecule
What are the 4 main types of proteins?
enzymes, antibodies, transport proteins, structural proteins
What is the test for proteins?
place sample in a test tube and add equal amounts of copper sulphate and sodium hydroxide and mix gently
What is the positive test for proteins?
blue to purple
What is an example of a globular protein?
haemoglobin
How many polypeptide chains make up haemoglobin?
four
How many atoms of oxygen can each haemoglobin carry?
eight
What is an example of a fibrous protein?
collagen
What amino acid does collagen have a lot of?
glycine
What is the quaternary structure of collagen?
three polypeptide chains wound together as a rope
What is the structure of a water molecule?
one oxygen atom attached to two hydrogen atoms
Why is water a polar molecule?
it has a partially negative charge on one side and a partial positive charge on the other
What is hydrogen bonding?
slightly negatively charged oxygen atoms attract slightly positively charged hydrogen atoms of other water molecules
Why is water a metabolite?
it is a substance involved in a metabolic reaction
How does water dissolve some substances?
it is a solvent, and because it is polar it surrounds the ion and dissolves it
What does it mean when water has a high specific heat capacity?
it takes a lot of energy to heat it up
What are the benefits of water having a high specific heat capacity?
it can help maintain constant body temperature
Why is high latent heat of vaporisation of water useful for living organisms?
it means they can use water lost through evaporation to cool down without losing too much water
How much energy does it take to break the hydrogen bongs between water molecules?
a lot
What does water being very cohesive help with?
transport water in plants and other organisms
What kind of surface tensions does water have?
high
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