Unit 1 Chapter 2: Basic Chem + Functional Groups Flashcards
Forms of an element with different numbers of neutrons are called?
Isotopes
The atoms that are most abundant in living cells are?
H,C, N, O, Na, Mg, P, S, Cl
List bond strengths in order
covalent>hydrogen/ionic>hydrophobic>van der waals
How does a covalent bond occur
sharing of electrons, when attractions overcome repulsions
What are hydrogen/ionic bonds
attraction of opposite charges
What are hydrophobic interactions
exclusion of non-polar molecules from water
What are van der waal’s attractions
interactions due to fluctuating electrical charges
What is bond energy
the energy needed to separate 2 bonded or interacting atoms under physiological conditions
Where do electrons in a polar covalent bond spend most of their time
close to the nucleus of the more electronegative atom
What is Adhesion
attraction between unlike molecules ie. water and a surface (force up)
What is cohesion
attraction between like molecules ie. water and itself (force down)
Which form of water is MORE dense
liquid, because ice forms a crystal lattice with gaps in between but liquid water does not
Does hydrolysis release or absorb energy
releases
Acids are…
proton donors
Bases are…
proton acceptors
Each increase/decrease in pH is how many times more basic/acidic
10 times
Buffers
- minimize changes in pH
- most are weak acids
What is the pH of solution inside cells
about 7
How many hydrogen bonds does each water molecule form as water freezes
4
What is Energy
the capacity to do work or supply heat
The kinetic energy of molecular motion is called
thermal energy
Temperature is
the average kinetic energy per molecule
Heat is
the transfer of thermal energy
The first law of thermodynamics is
energy cannot be created or destroyed, only transferred and transformed
The second law of thermodynamics is
the universe tends towards disorder
Reactions are spontaneous if (2 reasons)
- products have lower potential energy than reactamts (exo)
2. the products are less ordered than reactants(positive entropy)
For a spont. reaction free energy is
negative
An Amino (funt.group) is (+properties)
- NH2
- acts as a base
A Carbonyl (funt.group) is (+properties)
- aldehydes (end)
- ketones(middle)
- double bond O
- aldehydes react with compounds to make large molecules
A Carboxyl (funt.group) is (+properties)
- carboxylic acids
- double bond O, OH
- act as acids
A Hydroxyl (funt.group) is (+properties)
- alcohols
- OH
- highly polar, so makes compounds more soluble in H2O
- sometimes acts as a weak acid
A Phosphate (funt.group) is (+properties)
- when several of these are linked together, breaking P-O bonds releases a lot of energy
- P double bond O and 3 other Os
A Sulphydryl (funt.group) is (+properties)
- SH
- thiols
- can form disuphides (S-S) when present in proteins which contribute to protein structure
