Chapter 2 Flashcards
What are the types of bonds?
- covalent
- polar covalent
- non polar covalent
- ionic bonds
- hydrogen bonding
what is a covalent bond
when 2 atoms share pairs of electrons to complete their valence shells and reach stability
ionic bond
when the electronegatively for an atom is so strong that it is about to steal the electron away form the other. The electronegative atom that steals is called an anion. The one that is stolen from, is usually a metal and is called a cation.
polar covalent bonds
when one atom is more electronegative than the other, allowing is to pull the electrons closer to itself to create a dipole. Usually involving O, N and S
non polar covalent bonds
when the electrons are equally shared between both atoms in the covalent bond.
Usually involving C and H
what makes a bond weak?
When the energy to break the bond is larger than the thermal energy of them molecules themselves
what makes a bond strong?
when the energy to break the bond is smaller than the thermal energy of molecules themselves
what is hydrogen bonding?
When H is covalently bonded to an electronegative atom like C, N OR O, it becomes partially positive. Because of this, it can bond to another C, O or N in a reaction called hydrogen bonding
What is the strength of a hydrogen bonds?
they are generally weak as the thermal energy matches the energy of the bond. However, due to an addictive effect, the more bonds, the more it grows.
how does water act like a solvent
because it has both polar and non poplar sides, it can make polar molecules dissociate by attracting and surrounding them.
what is the hydrophobic effect
It is a thermodynamically favourable interactions that forces hydrophobic, non polar molecules to aggregate so they have less surface area interacting with the polar water molecules.
What is a van der waal interactions?
is the slight attractive force between molecules with dipoles
What are the life supporting properties of water?
- all 3 atoms can participate in hydrogen bonds
- both covalent bonds are highly polarized
- the structure is highly asymmetric
in room temperature…
non covalent interactions are constantly broken and reformed
which bond need more energy than visible light to break
covalent bonds
non polar molecules are
hydrophobic and do not dissolve in water because the water doesn’t seem any dipole from them
polar molecules are
hydrophilic because the water molecules sense their polarity
What makes a strong acids?
easily loses its H proton
a strong acid will have a _____ conjugate base
weak
a weak acid will have a ______ conjugate base
strong
What are macromolecules?
highly organized molecules that form structures that carry out activity in the cell
what are the 4 major categories of macromolecules?
- Nucleic Acids (made form nucleotides)
- Proteins ( made form amnio acids)
- Carbohydrates (made from monosaccharides)
- Lipids ( made from fatty acids)
What macromolecule is not always considered one and why?
Lipids because they are not always made be a repeat of monomer or connected to other monomers
What are functional groups?
particular grape of atoms that when together give a molecule specific properties, chemical reactivity and solubility in certain solutions.
What are biological molecules and what are they?
The organic molecules usually found in living cells but now its anything with C-C bond
- macromolecules
- precursor nucleotides
- metabolites
- miscellaneous function (viatmins, ATP and hormones)
Ketose
when the carbonyl is in the internal position (like fructose)
Aldose
when the carbonyl is in the external position (like glucose)
Why is glucose water soluble?
it has many hydroxyl groups
what is difference from normal and diabetic blood?
Diabetic blood has more sugars in the linear form which makes them react with hemoglobin
What are the characteristics of glucose?
- C6H1206
- In D position
- external carbonyl making it an aldose
what is carbohydrates used for?
- energy
- structural components of RNA and DNA
- structural components of cell walls of bacteria and plants
anomeric carbon
carbon 1, it is the carbon from the carbonyl carbon in the ketone or aldehyde in the linear form
alpha stereoisomers
the hydroxyl group is below the anomeric carbon
beta stereoisomers
the hydroxyl is above the anomeric carbon
Glycosidic bonds
when 2 monosaccharides link together by their hydroxyl groups on C1 on one and C4 on another
O- glycosidic bond
anomeric carbon connected to hydroxyl group (always alpha) usually to aparagine
N- glycosidic bond
anomeric carbon connected to nitrogen (always beta) usually to serine or theronine
maltose
2 alpha glucose, digestible for humans
cellubiose
1 alpha glucose, 1 beta glucose , non digestable because of beta bond
Glycoproteins
a N or O linked glycosidic bond covalently bonded between oligosaccharide and amino acid
Glycolipids
sphingosine lipid linked to a carbohydrate
What defines a nutritional polysaccharide and what is an example?
sugars that are stored and used for energy. An example is glucose being stored as glycogen in the liver.
Compounds produced by living chemicals are called?
biochemicals
Know the three common types of lipids
- fats
- steroids
- phospholipids
what are fats?
glycerol molecule made by 3 fatty acids connected by ester bonds
What are fatty acids?
long unbranched hydrocarbon chains with single carboxyl group
Saturated fats
they have no double bonds (no kinked)
unsaturated fats
they have some double bonds that makes them kinked
Characteristic if a fatty acid
they are amphipathic
- hydrophobic hydrocarbon group (tail)
- hydrophilic carboxyl group (head)
what is adipose tissue
it is in animals and its made up of adipocytes which are fate storing cells
Steroids
4 ringed hydrocarbon skeletons
Cholesterol
The precursor to steroid hormones
Phospholipid
2 fatty acids chains connected to a glycerol backbone and small polar group
Role of Proteins
carry out the cell’s activities
- enzymes
- signalling
- regulatory
- motor
- transport
Hydropathy Index
the solubility of the side chains
- positive is hydrophobic
- negative is hydrophilic
Level of organization for protiens
- amino acid
- alpha helix
- polypeptide chain
- assembled subunit
What bond links amino acids?
peptide bonds
What is a alpha helix
coiled cylindrical backbone of DNA
What is a beta sheet?
folded plated of polypeptides
What is a domain
a district part of a protein that has its own role that it contributes to the function of proteins. it folds independently and have a similar function in other proteins.
What is the role of chaperones?
molecular chaperones -stabilize the proteins
chaperonins - directly facilitate the folding
