Chapter 2 - Molecules of Life Flashcards
(19 cards)
What are the 5 important characteristics of water?
- Universal solvent
- Cohension & adhesion
- High surface tension
- High heat capacity
- Changes in density
Universal solvent
Due to intermolecular attraction to other polar molecules
Cohension and adhesion
Hydrogen bonds cause water molecules to stick together (cohesion) and polar bonds give water an adhesive property when water molecules cling to other polar surfaces
High surface tension
Water molecules at the surface are more strongly attracted to each other than the air above so they cling tightly to each other
High heat capacity
Helps stabilize large bodies of water and helps organisms maintain homeostasis
Changes in density
Water expands when it freezes causing it to have less density as liquid water; ice is less dense than liquid water
Diffusion
The movement of solute molecules from an area of higher concentration to an area of lower concentration
Osmosis
The movement of solvent molecules from a region of low solute concentration to a region of higher solute concentration
Dialysis
The process of separating molecules in a solution by the difference in their rates of diffusion through a semipermeable membrane
Marcomolecules
Large structures that make up all living organisms
Monomers
Single subunits that join using dehydration synthesis they bind together to make polymers (chain of monomers)
4 classes of macromolecues
Carbohydrates, lipids, proteins, and nucleic acids
Carbohydrates
- Main energy source for all organisms
Plant structure: - Monosaccharides - simple sugars (glucose, fructose, ribose)
- Polysaccharides - chain of monosaccharides that are the storage of starch, glycogen, and structural in plants
Lipids
- Have a variety of functions
- All hydrophobic
- Function: energy storage, membrane formation, and steroid function
- Have no real monomers
- Phospholipids form the cellular membrane
- Steroids contain all 6 hormones
Proteins
- Involved in nearly all cellular functions
- Amino acids: 20 different types
- Polypeptides: combine amino acids to get them and their function is structure
Nucleic acids
- Store, transmit, and express genetic information
- Nucleotides: adenine, guanine, thymine, and cytosine
- Polynucleotides: strands of DNA and RNA
Solute
Substance dissolved in a solvent
Solvent
The liquid in which a solute is dissolved to form a solution
What 2 things does diffusion depend on?
Temperature (particles dissolve faster in warm water) and particle size (smaller particles diffuse faster)
