Chapter 2.A - Molecular Biology Flashcards
Carbs contain?
CHO
→ H:0 2:1 ratio
Proteins contain?
CHONS
Nucleic acids contain?
CHONP
Metabolism
Web of enzyme catalysed reactions in a cell or oraganism.
Anabolism
Synthesis of complex molecules from simpler molecules = formation of macro-molecules from monomers by CONDENSATION reactions.
Catabolism
The break down of complex molecules into simpler molecules = HYDROLYSIS of macro-molecules into monomers.
Cohesive properties of water.
Binding together of water molecules to other water molecules
= useful for water transport in plants = sucked up through xylem tube!
Adhesive properties of water.
H. bonds from between water and other polar molecules = causing water to stick to them!
+ causes water to be drawn out of the nearest xylem vessel = keeps walls moist so CO2 can be absorbed for photosynthesis.
Thermal properties of water.
High specific heat capacity.
+ H. bonds restrict the motion of water molecules
+ increase in temp of water require H. bond to be broken. = needs energy = LARGE.
Why is water a thermally stable habitat for aquatic organisms?
Water’s temp remains relatively stable in comparison to air or land.
High Latent Heat of Vapourisation
When a molecule evaporates = separates from other mol. in a liquid = becomes vapour molecule = heat needed.
Why is water a good evaporative coolant?
Evaporation has cooling approach
+ It takes a considerable amount of heat = needed to evap. water = cuz the H.bond hv. to be broken
High boiling point of water
Boiling pt. is high
+ therefore water = liquid in a broad range of temperatures
+ 0 - 100 degrees celcius
How does water prevent charged or polar molecules from clumping together and keeping them in solution?
The polar nature of water molecules means they can form shells around the charged and polar molecules.
Hydrophobic interactions
Forces that cause non-polar molecules to join together.
If non-polar molecules = surrounded by water molecules what happens.
H. bonds form between the water molecules
+ NOT between the non-polar molecules and the water molecules
Monosaccharides
+ Glucose
+ Ribose
+ Fructose
+ Galactose
Dissacharides and what they’re made of
+ Maltose (Glucose + Glucose)
+ Sucrose (Glucose + Fructose)
+ Lactose (Glucose + Galactose)
Polyssaccharides and what they’re made of
+ Cellulose (beta glucose)
+ Starch (alpha glucose)
+ Glycogen (alpha glucose)
What type of bond is formed in condensation reaction between the 2 sugars?
Glycosidic bond (–O–)
What does C1 and C4 lose when 2 sugars bond?
C1 = loses OH C4 = loses H bonded to the O
The 2 types of polysaccharides in startch and their properties
+ Amylose = Chain of alpha-glucose
-Unbranched
-Forms and helix (As the Hydrogen’s repel each other to it coils up)
+ Amylopectin = Chain of alpha-glucose
-Branched
-Globular
Makes the energy more accessible = makes each glucose molecule more accessible and breaks down easier.
Cellulose properties and functions
+ Can form bundles w/ H.bond linking the cellulose molecules
+ Cellulose microfibrils = parallel to e.o
+ used to increase tensile strength → prevents cells from bursting
+ Basis of plant cell wall
→ important dietary fibre for humans when ingested (can’t digest)
Is amylopectin hydrophobic or hydrophilic?
Hydrophilic BUT is too large to be soluble in water so it can be used for storage
Properties of Glycogen and it’s function
+ Similar to starch BUT has more branchings
→ more compact
+ easy to add extra glucose molecule or remove a glucose molecule = done one both ends of unbranched molecule or any of the branched ones
+ Made by animals and some fungi
= stored in the liver and some muscles of humans = store of energy as glucose is soluble (SHORT TERM storage)
Fats physical state(s)
+ Liquid at body temp (37°C) → Adipose tissue
+ Solid at room temp (20°C)
Oils physical state
+ Liquid at BOTH room and body temp
Triglycerides are composed of?
3 fatty acids and 1 glycerol
→ by condensation reaction
What is lost from the fatty acid and what is lost from the glycerol when a ESTER bond is formed?
+ Glycerol loses H
+ Fatty acid loses hydroxyl group (-OH)
Why are LIPIDS preferred over CARBS for LT energy storage?
+ The amt of energy released in cell respiration is 2x that of carbs!
+ Mass advantage: Fats form pure droplets BUT 1g of glycogen has abt 2g og water
+ Lipids is 6x more efficient in the amt of energy stored/g of body mass
What are other uses of fats in the body?
+ Lipids are poor conductor of heat = good insulators
+ FATS = liquid at room temp → act as shock absorber
(adipose tissue around organs)
