Lecture 1.2 - Chemical Foundations of Life Flashcards
List the most common elements found in living organisms.
- carbon
- oxygen
- hydrogen
- nitrogen
- sulfur
- phosphorus
Explain why carbon is a key element for life.
this element is a key to life because it:
- can use its 4 valence (outer) electrons to form 4 covalent bonds w/ with hydrogen, oxygen, phosphorus, nitrogen, and even other carbon atoms.
- form chains, rings, and other complex structures by forming single bonds, double bonds, or triple bonds with another atom
electronegativity
the ability of an atom to attract an atom towards itself from an atom to which it is bonded
hydrogen bond
a bond formed between hydrogen and another element such as phosphorus, sulfur, oxygen, and nitrogen.
hydrophilic
polar compounds that readily dissolve in water
nonpolar
used describe bonds that have:
- electronegativity difference is less than 0.5
- electrons are shared equally
single bond
a bond with the capacity for rotation in whichch one electron is shared between 2 atoms
valence electrons
electrons located in outer most shell of an atom
water
a polar, bent molecule capable of forming hydrogen bonds
Determine how many covalent bonds a given atom can form based on the number of valence electrons it has
The number of bonds that an atom can form can often be predicted from the number of electrons needed to reach an octet (eight valence electrons)
Explain how and why atoms interact to form molecules.
n/a
Explain how the properties of water relate to the structure of water and why they make water important for life.
Water is the most important molecule for life because the chemical reactions required for life occurin water. Water is a small, bent, polar molecule that can participate in hydrogen bonding.
Describe the four types of noncovalent interactions in both words and pictures.
ionic
polar
nonpolar
n/a
acid
chemical species that donates protons or hydrogen ions and/or accepts electrons
amino
the functional group that consists of a nitrogen atom attached by single bonds to 3 hydrogen atoms
traits:
1. charged
2. basic= a proton acceptor
3. accepts H+ in living tissues NH3+
4. enters condensation reaction by giving up H+
cation
an ion that has lost one or more electrons, gaining a positive charge.
functional group
Functional groups have distinct chemical and physical properties that influence the behavior of the molecule to which the group is attached
organic molecules
molecules that contain carbon
polar covalent bond
bond between 2 nonmetal atoms that have different electronegativities and therefore have unequal sharing of the bonding electron pair.
ball-and-stick model
this molecular model displays both the three-dimensional position of the atoms and the bonds between them.
base
accepts a proton, releases a hydroxide anion when dissolved in water,
benzene
an organic chemical compound with the molecular formula C6H6.
carbonyl
draw and describe 2 forms
a reactive group that is the site of reactions that link aldehydes and ketones into larger, more complex organic molecules
- aldehyde
class of compounds: aldehydes
ex: acetaldehyde
- polar
- C=O group is very reactive
- carbon atom is double-bonded to one oxygen and singly bonded to one hydrogen
- important in buildings molecules and in energy-releasing reactions
- keto
class of compounds ketones
ex: acetone
- polar
- made of carbon double-bonded to an oxygen
- C=O group is important in carbohydrates and in energy reactions
carboxyl
a functional group with a carbon atom double-bonded to an oxygen atom and singly bonded to a hydroxyl group. The molecular formula is COOH.
class of compounds: carboxylic acid ex: acetic acids
characteristics:
1. charged
2. acidic; capable of being a proton donor
3. ionizes in living tissues to form COO- and H+ (or COOH)
4. enters into condensation reaction by giving up -OH
covalent bond
- this bond occurs when the orbitals of 2 molecules overlap in an energetically stable manner
- this type of bond involves the sharing of one or more electron pairs between atoms
- can also be represented in 4 ways
1. ball-and-stick
2. molecular formula
3. structural formula
4. space-filling model
double bond
a chemical bond in which two pairs of electrons are shared between two atoms.
element
a pure substance consisting only of atoms that all have the same numbers of protons in their atomic nuclei.
hydrophobic interaction
describes the relations between water and hydrophobes (low water-soluble molecules). Hydrophobes are nonpolar molecules and usually have a long chain of carbons that do not interact with water molecules. The mixing of fat and water is a good example of this particular interaction
hydroxyl
a functional group consisting of a hydrogen atom covalently bonded to an oxygen atom. The hydroxyl group is denoted by -OH in chemical structures and has a valence charge of -1. The hydroxyl radical is very reactive, so it quickly reacts with other chemical species. this group increase the solubility of compounds containing this group
- class of compounds: alcohols
- ex: ethanol
characteristics:
- polar
- forms hydrogen bonds with water to help dissolve molecules
- enables linkage to other molecules by condensation
ionic bond
the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element.
line-angle drawing
formulas imply a carbon atom at the corners and ends of lines. Each carbon atom is understood to be attached to enough hydrogen atoms to give each carbon atom four bonds.
methyl
these functional groups. contribute to hydrophobic and van de Waal interactions
class of compounds:
alkyl
ex: alaninw
characteristics:
* non-polar
* important in interactions w/ other non-polar molecules and in energy transfer
* highly stable
* consisting of a central carbon atom bonded to three hydrogen atoms
molecular formula
these formulas give the kind and number of atoms of each element present in the molecular compound
molecule
an electrically neutral group of two or more atoms held together by chemical bonds.
nonpolar covalent bond
equal sharing of the bond electrons arise when the electronegativities of the two atoms are equal.
organic molecules
molecules that contain carbon
phenyl
a cyclic group of atoms with the formula C6H5.
phosphate
a functional group that carries 2 negative charges
class of compounds: organic phosphates ex: 3-phosphoglycerat
characteristics
- phosphorus atom bonded to four oxygen atoms
- has three single bonds and one double bond
- charged
- acidic
- enters into condensations reactions by giving up -OH
- when bonded to another phosphate, hydrolysis releases much energy
polar
he electronegativity difference between the two elements needs to be between 0.5 to 1.6.
salt
The neutral ionic compound formed by the chemical combination of acid and base, or through neutralization.
space-filling model
The space-filling models are the most realistic. The size and position of an atom in a space-filling model are determined by its bonding properties
structural formula
Structural formulas identify the location of chemical bonds between the atoms of a molecule. A structural formula consists of symbols for the atoms connected by short lines that represent chemical bonds—one, two, or three lines standing for single, double, or triple bonds,
valency
ability of an atom or a group of chemically bonded atoms to form chemical bonds with other atoms or groups of atoms.
van der waals interaction
A weak force of attraction between electrically neutral molecules that collide with or pass very close to each other.
sulfhydryl
these groups are important in protein structure
class of compounds thiols ex: mercaptoethanol
characteristics
8 by giving up H, two -SH groups can react to form a disulfide bridge, thus stabilizing protein structure
