Biological Chemistry Flashcards
(28 cards)
how do cells vary?
appearance and function
how did living cells evolve?
from the same ancestral cell
what do genes do?
Provide instructions for the form, function, and behavior of cells and organisms
what makes a cell eukaryotic
nucleus with genome, membrane bound compartments, and cytoskeleton
how do cells vary enormously in appearance and function?
structure = function, so for their specific function, they have to be a certain shape (ie: a neuron is shaped like a tree with long branches to enable dendrites and axons to work well)
how do the domains of life form?
- prokaryotes - bacteria & archaea
- eukaryotes - eukaryotic cells
how do eukaryotes differ from prokaryotes
- euk cells are bigger and more complex
- they have a nucleus and a cytoskeleton
- they have extensive internal membranes
- bacterial cells have circular DNA
what are archaea?
they are found in extreme conditions, such as the bottom of the ocean floor
what is the endosymbiotic theory?
eukaryotic cells evolved by a primordial cell capturing other free-lving cells through phagocytosis
what are the five principles for the chemistry of biological systems?
- carbon
- water
- selectively permeble membranes
- polymerization of small molecules
- self-assembly
what is an element? atom? molecule?
- it cannot be broken down into other substances by chemical methods
- smallest unit with the properties of the element
- atoms held together by chemical bonds
why are CHONSP reactive?
- they have open electron spaces to fill and bonds to make
what is a covalent bond?
atoms that share electrons
why are covalent bonds not always equal?
due to electrongativity (oxygen is the most electronegative atom)
what is a polar covalent bond? nonpolar covalent bond?
- electrons are not shared equally
- electrons are equally shared
what is an ionic bond?
a bond between two atoms that results in either a gain or loss of electrons and it typically gneerates an ion
what are bond characteristics?
bond angle, bond length, bond strength
what are noncovalent bonds?
- they do not involve sharing eletrons and are relatively waker, transient (they can come together and apart quickly) and do not require enzymes
- examples include hydrogen bonds, hydrophobic interactions and van der Waals interactions
why is water important
- it is a universal solvent
- it forms polar, covalent bonds
- surface tension
- high boiling point
- high specific heat
- high heat of vaporization
what is an acid? base?
- any molecule, ion, or chemical group that donates H+
- any molecule, ion, or chemical group that combines with H+
what is ionic equilibria?
the measurable equilibrium between the weak acid and its conjugate base
what is the henderson hasselbach equation?
what does a larger Ka value mean?
the more the acid or base will likely be dissociated
pKa = -log(Ka)
How do acids and bases exist in conguates?
- HCl can donate a H+, and Cl- can accept that H+, hence Cl- is the conjugate base
- HA (acid/protonated) → H+ + A- (conjugate base, deprotonated, ionized)
