Module 6.1 Energy and Metabolism Flashcards
What occurs during chemical reactions?
Bonds are broken or formed and energy is absorbed or released.
What are the three types of chemical reactions?
- Combination reaction
- Decomposition reaction
- Recombination reaction
The left side molecules of a chemical reaction are called
reactants
The left side molecules of a chemical reaction are called
products
All chemical reactions MUST have the same number of
each element’s atoms on either side of the arrow.
How is the reaction CO2 + H2O → H2CO3 read?
1 molecule of carbon dioxide and 1 molecule of water combine to make 1 molecule of carbonic acid.
What indicates a reversible reaction?
A two-headed arrow.
What must all chemical reactions have?
The same number of each element’s atoms on either side of the arrow.
What is the first step in balancing chemical equations?
Write down the number of atoms of each element of the reactants and products.
Balance the equation: H2 + N2 → NH3.
3H2 + N2 → 2NH3.
What is the balanced version of the equation: NaOH → Na2O + H2O?
2NaOH → Na2O + H2O.
What is the balanced reaction for C6H6O3 + 3O2?
C6H6O3 + 3O2 → 6CO + 3H2O.
What is the balanced reaction for Na + 2H2O → H2 + 2NaOH?
2Na + 2H2O → H2 + 2NaOH.
How can a chemical reaction in a test tube be sped up?
- Increasing the concentration of the reactants
- Increasing the temperature of a reaction
Cells must depend on what to speed up chemical reactions
Enzymes
What are most enzymes made of?
Proteins or sometimes RNA.
What is the function of enzymes?
Speed up reactions in living organisms and act as catalysts.
Catalysts can be used
over and over again
An enzymes structure:
A folded molecule with a “pocket” or active site where reaction occurs
An equation that uses an enzyme
If there is something written above the arrow in an equation with an -ase ending, it is usually a
enzyme equation/reaction
In order for chemical reactions to occur, the reactants must first absorb
energy
What is the energy of activation (EA)?
The energy needed for reactants to absorb before a chemical reaction can occur.
Enzymes speed up reactions by
lowering the energy of activation
An enzyme is often a
protein with a pocket or active site
For enzymes, the reactants are called
substrates
The Enzyme Reaction process
- Substrates entering active site of the enzyme
- Reaction occurs making product
- Product leaves the enzyme
- Enzyme free to get more reactants and repeat
Enzymes are very specific—only certain substrates can
fit in the active site
True or False: Enzymes are very efficient-many times faster than chemical reactions without enzymes
True
True or False: Enzymes are used up during the reactions they catalyze.
False.
Enzymes do two things:
- bring molecules together (matchmakers)
- separate molecules (divorce lawyers)
Enzymes are (one word)
catalysts
What is the optimal temperature for enzymes in the human body?
37°C.
Enzymes work best at a given
temperature and pH
What is the optimal pH for most of the body’s enzymes?
Around pH 7, which is neutral.
Enzymes in certain parts of our body like to work in pH
2
What are the two types of energy?
- Kinetic
- Potential
ATP powers nearly all
form of work in cells
Potential energy:
Potential to do work. Is stored energy
Kinetic energy:
Does work. Is energy of motion
What happens when the third phosphate bond in ATP is broken?
A small amount of energy is released.
What does ADP stand for?
Adenosine diphosphate.
When the third phosphate bond in ATP is broken and energy is release, it makes
ADP with 2 phosphates and inorganic phosphate
How is ADP compared to ATP?
ADP is like an uncharged battery with low energy.
ATP-ADP Cycle graphic
