Energy and enzymes Flashcards
What is energy required for in the body?
for growth, repair, breathing, brain function, reproductive processes,
why do cells need energy?
to import materials to the body, make new materials and repair damaged parts
what is the importance of carbohydrates within energy?
-consumption of carbs allows sugar to be absorbed and generates energy that can be used by athletes
what is energy?
the capacity to work
what are the 3 different types of work?
-chemical work
-transport work
-mechanical work
what is chemical work and give an example?
-the breaking and making of new chemical bonds
-These allow us to grow and maintain homeostasis and adapt to our environment, store fuels (carbohydrates and fats) needed for future activities
Eg.the joining of amino acids to form proteins and water being removed
what is transport work and give an example?
-enables cells to move ions, molecules and large particles through the cell membrane (allows us to transport information around body)
-helps body to maintain homeostasis and helps to create concentration gradient by distribution molecules so concentration is higher on one side of membrane than the other
Eg. calcium concentration in muscle is higher than inside sarcoplasmic reticulum and natural concentration gradient allows calcium to move inside SR and then be released back into muscle driving contraction
what is mechanical work?
-used for movement processes
-eg.actin and myosin filaments joining together allowing for muscle contraction and relaxation-sliding filament theory
what are the 3 types of energy?
-thermal
-mechanical
-electrical
Within energy what 2 different forms can it come in?
-potential and kinetic
what is the difference between potential and kinetic energy?
-potential-stored energy when stationary
-kinetic-energy of motion
-Potential energy has to be converted into kinetic energy to become available
Describe how energy is stored and transported within biological systems?
-potential energy is stored in concentration gradients and chemical bonds
-is transformed into kinetic energy when needed for chemical, transport or mechanical work
Eg.glucose moving into muscles to be used (kinetic) glycogen is stored in muscles (potential)
What is the effect of chemical reactions on energy?
-they transform the potential energy of a chemical bond into kinetic energy for growth
-this is how cells obtain energy from the store of energy in chemical bonds of biomolecules
eg.ATP being converted to ADP by th removal of phosphate and the addition of phosphate and energy
From food to create ATP
What is a the potential energy stored in a chemical bond equal to?
potential energy stored in a chemical bond= a molecules free energy
what is a chemical reaction?
when one substance is turned into another by the breaking/ making of covalent bonds
how are covalent bonds formed?
by the movement of electrons
what are the 3 different types of chemical reactions?
-combination reactions (2 reactants into 1 product)
-decomposition reactions (breaking down of 1 product into 2 reactants
-displacement reactions (rearranging of reactants to form products)
what is activation energy?
-Activation energy is required for chemical reactions to occur
-is the energy needed to start a reaction (low activation energy means reactions are easier to start, may even be spontaneous)
What can reactions be separated into?
-Exergonic and endergonic
what are exergonic reactions?
- release of energy due to products having less energy than reactants
(heat is given off as a result, eg. ATP-phosphate is broken away to produce ADP, additional energy is released therefore allows us to use this energy in movement)
what are endergonic reactions?
products have more energy than reactants so energy is taken in (activation energy is trapped in the products)
What state can reversible reactions reach and what does the reversibility depend on?
-Reversible reactions reach equilibrium
- -the possibility of it being reversible depends in the net free energy change
What are enzymes and what do they do?
-biological catalysts- speed up chemical reactions without being changed by lowering the required activation energy
-are proteins
-substrate + enzyme = products + enzyme
how is reaction rate determined?
by speed of disappearance of products or appearance rate of products
what are the factors affecting reaction rate?
Heat- speeds up reactions-increases chance of 2 substrates meeting by putting more activation energy in the system
-Concentration of reactants- more of reactants-more likely to collide and react
how do enzymes work
-Enzymes bind to substrates at active sites. -They are specific and only bind certain substrates for certain reactions.
-Without enzymes, most metabolic reactions would take much longer and would not be fast enough to sustain life.
What 2 factors can impact enzymes?
-Enzymes are sensitive to temperature and pH
-enzymes optimum tmp is 40c (near 37c-core body temp)-above 60c or below freezing enzymes can’t function and can’t carry out chemical reactions (reactions slow down)
-optimum pH around ⅞-neutral
what happens to enzymes if they are not in optimum conditions
-they become denatured-active sites are no longer correct shape so cannot bind to substrate
What can change the shape of an enzyme?
-they can be activated/deactivated by conformation as an activator/ deactivator binds to the enzyme and changes its shape
