2. water carbs and proteins continued Flashcards
What is a glycosidic bond?
-Bond between sugar molecules to form carbs
What is an Ester bond? 4
found in lipids
links fatty acids to glycerol
Triglycerides have 3 Ester bonds
phospholipids have 2 ester bonds
What is a peptide bond?
joins amino acids together to form proteins
What is collagen? 3
-Most common protein in animals
-insoluble
- fibrous
What elements make up proteins? 4
Carbon, oxygen, hydrogen, nitrogen
How is shape of polypeptide chain maintained when coiled into an alpha helix?
hydrogen bonds
What is secondary protein structure? 4
-Formed when hydrogen bonding occurs between Oxy of C=O group on one amino acid
-And hydrogen-NH group on another amino acid further along the chain
-Result is formation of alpha helix & beta pleated sheets
-some areas of polypeptide will have neither structures & remain random coils depending on R groups present
Describe tertiary structure 5
-Caused by bonds forming between R-groups on amino acids that lie close to each other
-happens when chain starts to coil
-Creates 3D structures
-held firmly in place by bonds (must name in exam)
- tertiary structure gives active site its precise shape in enzymes
What bonds hold the 3D tertiary protein structure together? 4
hydrogen, disulfide, ionic bonds & weak hydrophobic interactions
What does high specific heat capacity do in body?
prevents wide variations in body temperature
What does strong cohesive forces between water molecules do 2
-creates surface for insects to walk on
-transpiration pull in xylem
What is high heat of vaporisation?
the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature
What does high heat of vaporization in water do to help sustain life
major component
of sweat used in
heat loss
Water is solvent for polar molecules and ions, what does that do to sustain life?
transport medium in blood plasma and phloem
22 What is bond at X
alpha 1,6 glycosydic bond
What are advantages of mammals having highly branched storage molecules? 3
-many ends for attachment & removal of glucose
-means glucose can be stored more quickly & accessed faster
-Good for when energy requirements lead to higher respiration demands
features of starch? 3
-glycosidic bonds between monomers
-stored within chloroplasts
-exists in two forms - branched and unbranched chains
describe how the structure of glycogen differs from the structure of amylose 3
-glycogen is branched molecule
- glycogen has 1,6 and 1,4 glycosidic bonds
-glycogen not coiled into helical shape
describe the advantages for organisms in storing polysaccharides, such as glycogen, rather than storing glucose 3
- Storage polysaccharides are compact so lots of glucose can be stored
-Storage polysaccharides are unreactive (unlike glucose)
-have osmotic effect on cell bc insoluble
Draw annotated diagram to explain how a glucose molecule is formed from the free end of the glycogen molecule
pg 15 model answer
Explain what is meant by the term primary structure .
sequence of amino acids in polypeptide chain
pg 17 The molecular structure of the first two amino acids of lysozyme, lysine and valine, is shown below.
Use the space to show how these amino acids become linked in a condensation reaction.
pg 17
What breaks a peptide bond?
hydrolysis- addition of water
Describe disulphide bonds 4
-broken by reducing agents
-formed between sulphur atoms
-Form between cysteine R groups in proteins
-strong covalent bond
