biological molecules Flashcards
What is a ‘polar’ molecule?
A molecule that has an uneven distribution of electron density
What part of the water molecule has a partial negative charge?
oxygen atom
What part of the water molecule has a partial positive charge?
Hydrogen atoms
Since water is a polar molecule, what does it attract?
Other polar molecules
Why is it important for living organisms that water is a good solvent?
Allows chemical reactions to take place in solution
It can act as a transport medium
(blood transports many substances) (water transports dissolved substances in the xylem and phloem of plants)
What does oxygen in water become attracted to when mixed with sodium chloride?
Sodium
(oxygen is partially negative and sodium is positive, therefore they attract each other)
What is cohesion?
Cohesive force is the property of like molecules sticking together, being mutually attractive
What is high surface tension?
cohesion between the water molecules at the surface produces surface tension
(allows insects to walk on water)
What does cohesion enable in living organisms?
Allows water to flow, very important for transmitting substances
What does it mean if water has a high specific heat?
A large amount of energy is needed to raise the temperature
Good for organisms that live in water because the temperature wont raise
What does it mean if water has a high latent heat?
A large amount of energy is needed to change it from liquid to gaseous state
It takes a large amount of energy for sweat to evaporate taking temperature down more efficiently
Why is important that water transparent?
Because light needs to go through for photosynthesis
Why is it important that ice is less dense than water?
Because ice acts as an insulator
What are the 4 most common elements in living things?
Hydrogen
Nitrogen
Carbon
Oxygen
What are the 3 elements in carbohydrates?
Carbon
Oxygen
Hydrogen
Whats the basic formula for carbohydrates?
(CH2O)n
How many carbon atoms does Triose have?
3 Carbon atoms
How many carbons does pentose have?
5 carbon atoms
How many sugars does Hexose have?
6 carbon atoms
What are the two different isomers of glucose?
alpha and beta
Whats the difference between alpha and beta glucose?
Different structural formula (learn it!)
What are the main functions of monosaccharides?
Energy in respiration
Building blocks for larger molecules
What are disaccharides?
2 monosaccharide units joined together
What is hydrolosis?
water splitting
(A chemical breakdown of a compound due to reaction with water)