Biology 2: Biochem Flashcards
Molecule
2 or more atoms joined together.
Atoms bond with other atoms…
to become more stable and to fill their outer energy levels
Ionic Bond
one atom “steals” electron from another
Covalent Bond
atoms “share” electrons
Polar Molecule
molecule with a positive and a negative end
it’s atoms do not share electrons equally
Hydrogen Bond
the hydrogen (positive) end of a polar molecule is attracted to the negative end of another molecule (often O or N)
Cohesion
polar water molecules are attracted to each other, and this creates surface tension
Adhesion
polar water molecules are attracted to other polar molecules
Surface Tension
caused by cohesion, “skin” on the surface of water
Cohesion + Adhesion
keeps molecules organized inside cells
allows H2O to move against gravity in plants
Temperature Moderation
adding heat makes molecules “twitch” faster
hydrogen bonds moderate movement
areas near water have a more stable climate
evaporation helps organisms maintain homeostasis
Low density of ice
lose thermal energy => molecules slow down => H bonds lock them in place in a grid => molecules are farther apart, so they are less dense and the ice floats
Water is good at dissolving because…
it’s polar!
Solution
uniform combination of two or more substances
Solute
thing that gets dissolved
Solvent
thing that does the dissolving (pulls ions away)
Polar charges…
on H2O molecules are attracted to charted regions of other polar molecules
For something to dissolve,
the attraction to water must be greater than the attraction to itself
The solvent used by organisms…
water
In solutions…
a few H2Os split into ions
Acids
pH<7 add H to solution
Bases
pH>7 remove H from solution
Buffers
substances that help organisms maintain pH homeostasis
Carbohydrates Composition
2 Hydrogen, 1 Oxygen, 1 Carbon
Carbohydrates Root
Sugar molecules
Examples of Carbs
Pasta and potatoes
Starch
source of energy, basic element of diet, animal energy storage
Monosaccharide
a single sugar unit (glucose)
Disaccharide
two monosaccharides (sucrose)
Polysaccharide
many monosaccharides
Glycogen
animal polysaccharide; energy storage, branched chain
cellulose
plant polysaccharide; building block
Organic
Carbon based
Inorganic
non-carbon based
Why is Carbon so important?
It can bond with 4 other atoms
It usually forms stable covalent bonds
It easily forms long, branched, or ring shaped compounds
Monomer
building block molecule
Polymer
longer chains of monomers linked together
Lipids
Fats that avoid water
Lipids composition
Carbon, Oxygen, Hydrogen
Saturated Fat
contains the max amount of H atoms, animal, solid
Un-Saturated Fat
contains less than max amount of H atoms, plant, liquid
Hydrophobic
Water fearing
Hydrophilic
Water loving
Steroid
cholesterol, 4 rings fused together, hormones
Why are Lipids important?
they cushion organs
store energy
provide the body with insulation
Proteins Composition
Hydrogen, Oxygen, Carbon, and Nitrogen
Why are Proteins important?
they control chemical reactions
they are the main thing in muscle
Amino Acid
central carbon atom bonded to 4 partners
Poly Peptide
several amino acids
Denaturation
an unfavorable charge that causes the protein to lose shape
Activation Energy
energy needed to activate a chemical reaction
Catalysts
the trigger that speeds up chemical reactions by lowering their activation energy
Enzymes
the catalysts of chemical reactions in organisms
- proteins with specific shapes
- each catalyses only one specific kind of substrate
- can be used over and over
Substrate:
what an enzyme works on
Active Site
area on an enzyme where its substrate fits and reactions occur
-ase
enzyme
-ose
substrate
