1. Chapter 5
The Working Cell

2. All about Energy...

3. Understanding Energy Energy: what gives the ability to do work
_________
Heat
Chemical

4. Kinetic Energy: The energy of motion
Actually using up stores of energy in order to move matter
Riding a bike, falling, running
Heat and light are also forms of kinetic energy because they are _______ __________ ___________ _________… they are signs that energy is being used… byproducts

5. Potential Energy: what could happen
No motion… just the POTENTIAL for motion
______________: When PE is due to the arrangement of molecules and their potential to allow work to get done
Most important type in living system
Only useful when transformed

6. A short quiz… choose potential or kinetic

7. Thermodynamics… the study of energy
Energy can change forms…
from chemical (the food you eat) to _________ (motion)
From light (sun) to _________ (sugar) in plant photosynthesis
From chemical (wood) to heat (burning)
From electrical to light (light bulb)
From wind to _______________ (electric wind mills)

8. All of energy behaves according to two laws…
First law of thermodynamics: The total amount of energy in the universe is ___________ (energy cannot be created or destroyed)
Second Law of Thermodynamics: Energy conversions _____________ of the universe (Entropy)

9. Neither created or destroyed
All energy must be transferred… for every bit of energy put in there has to be that much coming out
Excess is usually associated with __________

10. More on Entropy
It is __________ (doesn’t require energy) to lose order
It takes _______ to gain order
Therefore the progression of time leads to disorder

11. Endergonic vs. Exergonic
A reaction that takes in energy is ________ (the products are at a higher energy level– not spontaneous)
A reaction that releases energy is ___________ (the products are at a lower energy level-- spontaneous)
The form of energy can vary– heat (endo or exothermic) light, or even movement.

12. When Cells use energy its called ATP
Adenosine triphosphate: Molecule that stores energy in a high energy phosphate bond… ________, 5 carbon sugar and 3 phosphates
Once it transfers the energy of the bond it is ______ (adenosine diphosphate)
That is the exergonic part… then is uses the energy to run an endergonic part
ADP = greater disorder

13. Coupling
When an exergonic and endergonic reaction are paired to create a product
When this is done with ATP it is called _______________
High energy phosphate is transferred to another molecule, then broken off to provide ______ for the next reaction

14. Enzymes help us use less energy
Activation Energy is the amount of energy to get started
Enzymes lower ____________ _________
Like getting a push on the swings, it doesn’t take much energy to keep it going once you start but starting can be hard.
Otherwise getting started would take to long… you would starve before you could use the food energy

15. How enzymes work
They have an ACTIVE SITE that allows a particular SUBSTRATE to bind
It _________ the reaction between or within substrates
Then it lets go of the new product… because the change makes it _________ ______ in the active site

16. Enzymes are not always active
To time a particular activity there are times when enzymes are active, or inactive
Cofactors (_________) and coenzymes (________) speed up enzymatic activity
Vitamins, minerals, pH, temperature all can effect activity
Act on _________ ______ or on area around the enzyme
Cofactor or coenzyme?

17. How to inhibit an enzyme
Can either establish an ___________ inhibitor (competes for the active site)
Or a ____________ inhibitor (binds to allosteric site and alters the active site so the original substrate cannot bind)

18. Some other things inhibit enzymes
Pesticides, antibiotics, and other chemicals sometimes inhibit enzymatic processes
CO is a competitive inhibitor for O2 binding to hemoglobin
We use this idea to fight disease… we have competitive inhibitors for bacteria proteins (penicillin)
We are looking for more… maybe the key to AIDS cure

19. Negative feedback
This is when the ________ of the enzyme acts a an ________, either competitive or noncompetitive
This stops the enzyme from making too much product

20. All about membranes

21. A review of basic membrane information
Made primarily of phospholipid bilayer (hydrophilic heads, hydrophobic tails)
________________: some things (lipids/fat soluble and really small) can get through some cannot (water soluble/ larger)

22. Fluid Mosaic model of the membrane
Containing phospholipids, carbohydrates and proteins all in ________ and constantly rearranging

23. The proteins transport other molecules
Integral proteins can be
Enzymes, catalyzing reactions on the membrane
Signal ____________, a messenger that tells the inside what the outside of the cell said
___________, let certain molecules, that would otherwise be trapped, through the membrane

24. Types of transport Passive: no ATP necessary Active: requires ATP
Diffusion: movement of ________ along their concentration gradient
Osmosis: movement of _______ along its concentration gradient
Facilitated diffusion: movement along a concentration gradient helped by a ________ _______
Active: requires ATP
Moves against concentration gradient… usually through protein
Endocytosis/ exocytosis: brining in or out of large molecule… to big to fit through a protein

25. Water balance
Osmosis remember is the movement of water along its concentration gradient
The problem comes when the water moves too quickly and shrinks, or explodes the cell
Isotonic a solution that is the same concentration as the cell itself (regular)
Hypotonic is when _____ concentration of water is _______ the cell so the water rushes in (swollen)
Hypertonic is when the _____ concentration of water is ________ the cell so water tends to rush out (shriveled)

26. Endocytosis/ exocytosis
When a molecule is too big to fit though a membrane protein it has to be engulfed into the cell or spewed out of it
____________: bringing into the cell
Phagocytosis: cell eating
Pinocytosis: cell drinking
Exocytosis: taking ______ of the cell

27. Don’t forget– most of this took energy
Every bit of ATP we use needs to recycled into ADP…
Recycling because of the first law of thermodynamics
That takes work (reversing entropy)
ATP is made in the membrane of mitochondria… that will be discussed more next chapter!