molecules Flashcards
What elements do carbohydrates contain?
carbon, hydrogen and oxygen
What 3 groups are carbohydrates classified in?
monosaccharides, disaccharides and polysaccharides
What do monosaccharides include?
glucose, fructose and galactose
What are monosaccharides
a single sugar, mainly used in respiration to provide energy and growth during the formation of larger carbohydrates
What is a disaccharide?
when two monosaccharides are joined together by glycosidic bonds in a condensation reaction.
What’s a disaccharide formula?
C12H22O11
How can a disaccharide be broken down into its monosaccharides?
hydrolysis reaction
How can disaccharides be hydrolysed?
by boiling with acid or heating with an enzyme at an optimum temperature
3 disaccharides
maltose, sucrose and lactose
What are polysaccharides?
large polymers of monosaccharide molecules
3 polysaccharides
cellulose, starch and glycogen
What is the function of polysaccharides?
storage and structural
What’s provides rigidity and shape to the cell?
Cellulose
What’s cellulose made up of?
many beta glucose molecules joined together by condensation reactions to form long straight chains
What’s starch?
Storage carbohydrates found in plants, consisting of long alpha glucose molecules
Why is starch suited to its function as its storage compound?
- insolulble and therefore osmotically inactive
- helical shape forming a compact store
- contains a large number of glucose molecules providing an abundant supply of respiratory substrate
- it is too large to cross the cell membrane and remains where its formed
What is starch hydrolysed by?
the enzyme amylase to produce maltose
What’s glycogen?
the storage carbohydrate found in the cytoplasm of animal cells
Where’s glycogen stored?
in liver and muscles tissues
is glycogen insoluble?
yes
What do lipids contain?
carbon, hydrogen and oxygen
What’s triglycerides?
a type of lipid formed by joining 3 fatty acids to one glycerol molecule during a condensation reaction with the loss of 3 water molecules
What’s the general formula of a fatty acid?
R-COOH
What does R represent?
a long hydrocarbon chain
What does COOH represent?
a carboxylic acid group
what does hydrated mean?
no carbon double bonds in R group
How can lipids be hydrolysed into fatty acids and glycerol?
heating with acid or alkali and using the enzyme lipase at an optimum temperature and pH
What does a phospholipid molecule consist of?
one glycerol, two fatty acids and a phosphate group joined in a condensation reaction
Explain the formation of a phospholipid
The phospholipid molecule has a polar hydrophilic head (attracts water)containing the phosphate group, and a non polar hydrophobic tail (repels water) containing long fatty acids
What do proteins contain?
carbon, hydrogen, oxygen, nitrogen and sometimes sulphur
What are amino acids joined together by?
peptide bonds
what do 2 amino acids joined together make?
a dipeptide
name 3 fibrous proteins?
keratin in nails and collagen in bone
globular proteins
hormones, information role
quaternary structure of a protein
haemoglobin and antibodies
what does benedicts test for?
for reducing sugars
what colour does it turn if starch is present?
yellow/orange
what colour does it turn if protein is present?
purple
what colour does it turn if surose is present?
blue
