Biochemistry 1 Flashcards
What are the 6 atoms that make up 99% of all living organisms? From most abundant to least.
Most to least:
Oxygen, Carbon, Hydrogen, Nitrogen, Phosphorous, Sulfur
Matter
Any substance in the universe that has mass and occupies space composed of particles called atoms
What are the smallest unit of any given element?
Atom
What are atoms composed of? Which is the most important in bonding?
Protons (+), Electrons (-) and Neutrons (n0). Electrons are the most important in bonding because they are what pulls two atoms together.
6
C
Carbon
12.011
Label each component.
6 -> atomic number (# of protons and electrons)
C-> symbol
12.011 -> the mass number (protons + neutrons)
Isotopes
different forms of the same element that vary in the number of neutrons (different atomic mass)
-but they have the same properties
If a carbon isotope has 6e,6p, and 7n, what is it’s name?
Remember mass number = neutrons + protons
So 7+6=13
Answer: carbon-13
Why do isotopes have the same chemical properties?
Because they contain the same number of electrons
Radioisotopes
Radioisotopes are isotopes which their nucleus are so unstable they decay and give off radioactive particles
What are radioisotopes useful for?
-radioactive tracers
-nuclear medicine
-radiometric dating
-dna sequencing
What do isotopes of the same element differ and remain similar in? (summary)
Similar
-number of protons and electrons
-chemical properties
Differ
-the atomic mass
-the number of neutrons only
What is the chemical behaviour of an atom determined by?
It’s electron configuration in its outermost shell (valence/electron shell)
-atoms with incomplete valence shells are chemically reactive
Octet Rule
atoms tend to gain, lose, or share electrons so they have have a full valence shell
What are ions
Charged particles which are either positively charged (cation) or negatively charged (anion) which form by gaining or losing electrons
-between metal and non-metal
Covalent bonds vs Ionic bonds
Covalent - formed by sharing of electrons -> forms molecules
Ionic - transfer of electrons -> forms ions
What is VSEPR theory?
Valence shell electron pair repulsion theory (VSEPR)
-electrons try to get as far away from each as possible
-lone pairs of electrons take up more space than bonding pairs of electrons
Why does water have a bent shape?
VSEPR, the electrons repulse each other, the lone pairs on the oxygen molecule repulse the hydrogens making it asymmetrical
What is the electronegativity?
The measure of how strongly an atom is going to pull shared electrons towards itself
EN values of non-polar covalent, polar-covalent, and ionic compounds
NPC - 0-0.4
PC - 0.5-1-6
IB - EN > 1.7
non-polar covalent, polar-covalent, and ionic compounds
Non-polar -> symmetrical, equal sharing of electrons, no charge separation
Polar -> unequal sharing of electrons, charge separation
Ionic -> transfer of a charge (electron)
Why are compouds polar/nonpolar?
Due to their electronegativities, which is their ability to hold onto electrons, if an electronegativity is low then they just share it quite equally.
How to determine where the partial -/+ charges are
The more electronegative atom contains the partial negative charge
Ranking of bond strengths:
ionic > polar > non-polar
Why are polar molecules stronger than nonpolar molecules?
The symmetry, the type of bonds between, the atoms involved, etc.
Asymmetrical =
Symmetrical=
asym = polar
sym = non-polar
London Forces
Van der waal forces, they exist between all molecules and are the weakest ones
Explain water as an example of bonds (detail)
water is a covalent bond between H and O
-O is more EN therefore it contains the partial negative
-O attracts the hydrogen more than the hydrogen attracts O therefore it has asymmetrical strength
-water has a bent shape
Dipole-dipole forces
exist between polar molecules polar ends which attract each other
Hydrogen bonds
A type of strong dipole-dipole force which bonds together H-F H-O H-N
FON
Ion-dipole interactions
Form between an ion and a polar molecule
Example: hydration shells
Hydration shells
Polar molecules attract to the negative/positive charges on ions and form a shell to dissociate them.
Water dissolving NaCl
Hydrophilic vs Hydrophobic
Hydrophilic - water loving, polar charged molecules
Hydrophobic - water fearing, non polar molecules
Like dissolves like
polar molecules dissolve in polar molecules, etc.
Why do oil and water not mix?
When a nonpolar molecule such as oil with no charges on it are put in a polar molecule, the polar molecules are going to attract to each other’s charged ends which pushes the nonpolar molecules out of the way
Liquid vs solid water
-when is water most dense?
-which state is more dense?
-what structure does water form?
Water is most dense at 4C
Less dense as solid than as liquid
This means ice can float on water
Water forms a water lattice
What is special about water at room temperature?
Water is liquid at room temperature due to its water lattice structure, which most molecules of similar size would be gases
Specific heat capacity
The amount of energy required to increases the temperature by 1 degree celsius
- a lot of energy is need to increase temperature of water
Cohesion vs adhesion
Cohesion - water molecules stick to each other well through hydrogen bonds
Adhesion - water molecules form hydrogen bonds with other polar molecules (sticking to container walls)
The four major types of chemical reactions that are common in biological processes are:
-condensation
-hydrolysis
-neutralization
-redox reactions
RCHN
What is surface tension a property of water?
Cohesion
How is high specific capacity beneficial for organisms?
It helps organisms maintain a steady body temperature
What happens when pH levels change in the body?
must be maintained at very exact level, if it changes it could denature proteins and enzyme function
Buffers
used to control pH levels inside cells since they can absorb or release H+ ions
What kind of buffers are in blood?
Bicarbonate buffers
Why is carbon so special?
-4 covalent bonds
-can form long chains that can be straight or branched
-can form ring structure
-it can form branches in up to four directions
-can bond to itself or other atoms
Hydrocarbons
contain only carbon and hydrogen
Alkanes, Alkenes, Alkynes, cyclic
Alkanes = all single bonds
Alkenes = one or more double bonds
Alkynes = one or more triple bonds
Cyclic = ring structures
Functional groups
group of atoms on HC chains that give molecules certain physical properties
Dehydration synthesis reactions
removing water to combine two molecules (condensation reaction)q
Hydrolysis Reactions
breaking apart molecules with water
Carbohydrates use
-quick, short term forms of energy
-important for structural molecules
-sugars and simple starches/sugars
Carbohydrates ratio
1:2:1
C1:H2:O1
Monosaccharides
+ 3 main types
Simplest type of carbohydrate found in cyclic structures in cells, they consist of single sugar units; building blocks for more complex carbohydrates
-glucose, fructose, galactose
Disaccharides + three main types
A carbohydrate molecule that consists of two monosaccharides
-sucrose, lactose, maltose
What happens when monosaccharides linear are in water?
They form ring structures especially by the functional groups react with each other
isomers
a molecule that has the same chemical composition, but different arrangements of atoms
Types of glucose
alpha and beta glucose
Alpha - the OH on the right side is down
Beta - the OH on the right side is up
Why are sugars so soluble in water?
They have a lot of functional groups attached to them
Draw glucose and galactose
Draw
What’s the difference between glucose and galactose? What are these called?
Glucose and galactose are isomers, they have the same chemical formula, but different properties
LEFT SIDE
-galactose the OH is up
-glucose the OH is down
How are disaccharides brought together
By dehydration synthesis reactions
How does maltose form
1-6 or 1-4 alpha linkage of two alpha glucose molecules
What kind of bond links together monosaccharides
Glycosidic bonds
How does lactose form
galactose + glucose
How do you tell if a glycosidic bond is alpha or beta
The orientation of the -OH group on the first carbon
Solubility of types of carbohydrates
Mono - very soluble (functional groups)
Di - they are also soluble
Poly -they are hydrophilic (attract water) but since they are so long they don’t dissolve in water
Types of bonds that can form maltose
1-4 alpha glycosidic bond
or
1-6 alpha glycosidic bond
Draw hydrolysis and dehydration synthesis of two alpha glucose
draw
Polysaccharides + main functions
Complex carbohydrates that is composed of hundreds to thousands of monosaccharides linked together
-provide structural support and energy storage
Types of macromolecules
proteins, lipids, carbs, dna/rna
Polymerization
when monomers link together through dehydration synthesis to form long chains of a larger molecule
Celluose structure and function
Structural support in plants cell walls
Made of b-glucose units that flip opposite ways
also known as fibre
Difference in how cellulose and starch affect our bodies
We have enzymes that digest starch and turn it into glucose monomers but not cellulose so it comes out in excretion
Starch function
Starch is an energy storage molecule in plants
Types of starch molecules and their difference + the difference in looks (draw)
both glucose
Amylose -> straight chains alpha 1-4 GB (curly and straight)
Amylopectin -> branched a 1-4 a-1-6 GB (branched)