Topic 9 (Electronegativity) Flashcards
Atoms with a high electronegativity have
A higher affinity for electrons
Oxygen is always trying to
Steal electrons
What is a polar covalent bond?
Electrons are shared unevenly (ex: H2O)
What is a non-polar covalent bond?
Electrons are shared evenly
ex: O2, H2, CH4
What type of molecule is water and what bonds does it form?
Water is a polar molecule. It forms hydrogen bonds
What is bond energy?
The amount of energy required to break a bond
The amount of energy that is released when a bond is formed
What bonds have a higher bond energy? Polar covalent or non-polar covalent bonds
Polar covalent bonds
What has the highest bond energy and the lowest?
Lowest: C-O
Highest: C=O
Define metabolism
The set of chemical reactions that occur in cells to maintain life
What is a catabolic reaction?
It is when energy is released from breaking down complex molecules into simpler compounds
Define anabolic reaction?
Consume energy to build complex molecules from simpler ones
What is the energy currency of the cell?
ATP (Adenosine Triphosphate)
ATP –> ADP
When ATP (high energy) is broken down into ADP (low energy), energy is released
ATP
When ADP + Pi are combined to make ATP, energy is stored
How do enzymes speed up metabolic reactions?
They lower energy barriers
What is energy activation?
In living cells, the energy needed to start a reaction (to break bonds for instance) is lowered by enzymes
What is the enzyme responsible for degrading peptidoglycan
Lysozyme
What is the enzyme for penicillin?
Penicillinase
What does DNAse do?
‘Digests’ DNA
What does Proteinase do?
Digests protein (aka protease)
What does ATP synthase do?
Synthesizes ATP
What does Reverse Transcriptase do?
Used by HIV virus to transcribe its RNA genome to DNA
What does Integrase do?
Enzyme used by HIV to integrate its genome into host cell’s genome
What is a substrate?
The reagent to which the enzyme binds (the starting material)
How would you express an enzyme controlled reaction
Substrate(s) —- Enzyme –> Product(s)
What do enzymes do to reactions?
Catalyze them
How do enzymes speed up reactions? (2)
- Align the reagent(s) properly
- Lower the amount of energy needed for reactions to occur
What happens at the active site?
It is where the action is. At the active site cleft that binds single strand of DNA and makes the double strand
What is dehydration synthesis?
Stealing water builds a more complex molecule (and requires energy)
What is usually added/removed when enzymes build or disassembling molecules?
Water
Define hydrolysis
Adding water breaks the molecule and there is a net release of energy (more energy is released by the formation of H2O)
Enzymes can.. (3)
- Build Molecules
- Break them down
- Transfer things
What needs to be specific for an enzyme to function (7)
- Temperature
- pH
- Substrate concentrations
ALSO: salt concentrations, product concentrations, different organs, cell compartments
Name 3 ways proteins can be denatured
Changes in: heat, pH, or chemicals
What is competitive binding?
Bind at the same location as substrate
What is non-competitive binding?
Bind somewhere else and disrupt active site or bar entry into active site (allosteric regulation) *see slide 32 for pic
How do inhibitors bind?
Reversibly or irreversibly
What is an example of an inhbitor?
Sarin: binds covalently to serine
What does the inhibitor ASA do?
It binds reversibly to an enzyme that forms prostanoids responsible for swelling and pain
What does the inhibitor Pen G do?
Binds covalently (irreversibly) to enzymes involved in bacterial cell wall biosynthesis
- Lethal to the bacteria
- Does not affect our cells (no cell walls)
The Citric Acid Cycle (AKA the Kreb’s Cycle) details
- Pyruvate broken down to CO2
- 2 ATP
- 8 to 10 electrons passed to carriers
In the Citric Acid you get… (end products)
6 NADH + H+ 2 FADH2 4 CO2 2 ATP Regenerate oxaloacetate for next "turn of the wheel"
