1. Chapter 5
The Working Cell

2. Fireflies use ___________ to send signals to potential mates
Intro: Cool “Fires” Attract Mates and Meals
Fireflies use ___________ to send signals to potential mates
Instead of using _________ signals like most other insects
The light comes from a set of chemical reactions, that occur in light-producing organs at the rear of the insect.

3. Energy is the _________________________________
ENERGY AND THE CELL
Energy is the _________________________________
All organisms require ___________ !
(“ability to obtain and use energy” was a defining characteristic of living things!)
What is Energy?

4. ___________ energy is the energy of motion
___________energy is stored energy, which can be converted to kinetic energy.
Rollercoaster animation
Figure 5.1A–C

5. Two laws govern energy transformations
___________________ : the study of energy transformations
The _______ Law of Thermodynamics
Energy can be changed from ______________________________, but energy ________ be ___________ or ____________.
Figure 5.2A

6. Energy for cellular work
The _____________ Law of Thermodynamics
Energy transformations ___________ __________or entropy, and some _________________ __________________
Heat
Chemical reactions
Carbon dioxide
Glucose + +
ATP
ATP
water
Oxygen
Figure 5.2B
Energy for cellular work

7. Chemical reactions either _________ or ___________ energy

8. ______________ reactions - ________________ and yield products rich in _________ energy.
Potential energy of molecules
Reactants
Energy required
Products
Amount of energy required
Figure 5.3A

9. ______________ reactions - _________ energy and yield products that contain _______ ____________ energy than their _____________
Reactants
Energy released
Products
Amount of energy released
Potential energy of molecules
Figure 5.3B

10. __________________ - Uses _____________ reactions to fuel ____________ reactions. This is how cells carry out thousands of chemical reactions! (cellular metabolism)
Endergonic and exergonic

11. Currency of the cells
Energy is like a __________ __________ , with ________ being the “currency” for the cells.
You either save $ or you withdraw $!
You cells can either _________ (save $) _________ by ________ bonds OR __________ (withdraw $) __________ by __________ bonds!
Can only do one or the other
at any given time!

12. ________ (adenosine triphosphate) powers nearly all forms of _________ __________
The energy in an ATP molecule lies in the _________ between its __________ groups.
Phosphate groups
ATP
Energy P
Hydrolysis
Adenine
Ribose
H2O
Adenosine diphosphate
Adenosine Triphosphate +
ADP
Figure 5.4A

13. ____________ a phosphate; breaks the bond = __________ of energy.
________________ = adding a _________ group to make molecules more reactive by _________ energy.
ATP
Chemical work
Mechanical work
Transport work P
Molecule formed
Protein moved
Solute transported
ADP +
Product
Reactants
Motor protein
Membrane protein
Solute
____________ a phosphate; breaks the bond = __________ of energy.
______ a phosphate; builds a bond = _________________ energy.
Animation
Figure 5.4B

14. Cellular work can be sustained because ATP is a ___________ resource that cells constantly ___________________!
ATP
ADP + P
Energy for endergonic reactions
Energy from exergonic reactions
Phosphorylation
Hydrolysis
Figure 5.4C

15. HOW ENZYMES FUNCTION
Enzymes __________ ______ the cell’s chemical reactions by _______________________________________
For a chemical reaction to begin reactants must absorb some energy, called the _______________________________________ (energy needed to get the reaction going)
EA barrier
Reactants
Products 1 2
Enzyme
Figure 5.5A

16. Progress of the reaction
A ___________ speeds up a reaction, by ___________ the energy of _________ needed to _______ a reaction.
Reactants
EA without enzyme
EA with enzyme
Net change in energy
Products
Energy
Progress of the reaction
Figure 5.5B

17. THEREFORE, ALL ____________ are catalysts!

18. An enzymes _______________ ________ determines which chemical reactions it will catalyze.1
Enzyme available with empty active site
Active site
Substrate (sucrose) 2
Substrate binds to enzyme with induced fit
Enzyme (sucrase)
Glucose
Fructose
H2O 4
Products are released 3
Substrate is converted to products
Animation 2
Animation 1
Figure 5.6

19. How?? What affects enzyme activity??
___________________ , ___________ concentration, and ________ influence enzyme activity and can affect its function.
How??
Some enzymes require nonprotein cofactors such as metal ions or organic molecules called ______________.
Ex. _________________

20. Normal binding of substrate
Enzyme _________ can ________ enzyme action
_________________ inhibitors- take the place of a substrate in the active site
____________ inhibitors alters an enzyme’s function by changing its shape
Substrate
Enzyme
Active site
Normal binding of substrate
Enzyme inhibition
Noncompetitive inhibitor
Competitive inhibitor
Many poisons, pesticides, and drugs are enzyme inhibitors.
Figure 5.8

21. Phospholipids have a _________ head and 2 __________ tails.
The plasma membrane of the cell is ________________ ____________ controlling the flow of substances into or out of the cell
Phospholipids have a _________ head and 2 __________ tails.
Phospholipid bilayer, with the heads facing
outward and the tails facing inward
CH2
CH3 CH N + O O– P C
Phosphate group
Symbol
Hydrophilic head
Hydrophobic tails
Water
Hydrophilic heads
Hydrophobic tails
Figure 5.11A

22. A membrane is a ________________ with ___________ , _________ and _________________ embedded in a phospholipid bilayer or along each side.
Fibers of the extracellular matrix
Carbohydrate (of glycoprotein)
Glycoprotein
Microfilaments
Phospholipid
Cholesterol
Proteins
Plasma membrane
Glycolipid
Cytoplasm
Figure 5.12

23. Membrane proteins can function as:
____________ - they help speed up chemical reactions for the cell.
____________ – bind and transmit chemical messages from other cells
_____________- moving substances across the membrane
ATP
Messenger molecule
Receptor
Activated molecule
Receptor site animation
Figure 5.13A

24. TYPES OF TRANSPORT ACROSS A MEMBRANE

25. NO ENERGY REQUIRED!
1) __________ transport- substances diffuse through membranes _____________________ ; spread from areas of __________ concentration to areas of ________ concentration
Small nonpolar molecules such as O2 and CO2
Diffuse easily across the phospholipid bilayer of a membrane (Diffusion animation)
Equilibrium
Membrane
Molecules of dye
Figure 5.14A
Figure 5.14B

26. Many kinds of molecules DO NOT diffuse freely across membranes
NO ENERGY REQUIRED!
Many kinds of molecules DO NOT diffuse freely across membranes
For these molecules, transport proteins MUST provide passage across membranes through a process called _______________ __________.
Solute molecule
Transport protein
Facilitated diffusion
animation
Figure 5.15

27. NO ENERGY REQUIRED!
____________ is the diffusion of ______________ across a membrane
In osmosis water travels from a solution of _________ _____________ concentration to one of __________ ________ concentration (higher water conc. to lower water conc.)
Lower concentration of solute
Higher concentration of solute
Equal concentration of solute
H2O
Solute molecule
Selectively permeable membrane
Water molecule
Solute molecule with
cluster of water molecules
Net flow of water
Osmosis animation
Figure 5.16

28. Shrink in _________________ solutions
The control of water balance is called __________________
Shrink in _________________ solutions
Swell in ________________ solutions
Equal movement of particles in _____________ solutions
(Animal cells are normal, but plant cells are limp)
Plant cell
H2O
Plasma membrane
(1) Normal
(2) Lysed
(3) Shriveled
(4) Flaccid
(5) Turgid
(6) Shriveled (plasmolyzed)
Isotonic solution
Hypotonic solution
Hypertonic solution
Animal cell .
Figure 5.17

29. Active transport- ENERGY REQUIRED!
__________ ___________ can move solutes _______ a concentration gradient through active transport, which requires ________ (One example of active transport is the sodium-potassium pump used in nerve impulses) P
Protein changes shape
Phosphate detaches
ATP
ADP
Solute
Transport protein
Solute binding 1
Phosphorylation 2
Transport 3
Protein reversion 4
Figure 5.18

30. ENERGY REQUIRED!
To move large molecules or particles through a membrane, a vesicle may fuse with the membrane and expel its contents (_________________)
Membranes may fold inward enclosing material from the outside (_________________)
Fluid outside cell
Cytoplasm
Protein
Vesicle
Vesicle forming
Figure 5.19A

31. Endocytosis can occur in 3 ways:
________________– cellular eating (animation)
_______________ – cellular drinking
Receptor-mediated endocytosis
Pseudopodium of amoeba
Food being ingested
Phagocytosis
Pinocytosis
Receptor-mediated endocytosis
Material bound to receptor proteins
PIT
Cytoplasm
Plasma membrane
TEM 54,000
TEM 96,500 
LM 230
Figure 5.19C

32. Enzymes are central to the processes that make energy available to the cell
__________- carry out photosynthesis using solar energy to produce glucose and oxygen from carbon dioxide and water
_____________ - consume oxygen in cellular respiration, using the energy stored in glucose to make ATP.
Overview animation
(We’ll go. into more detail on each process in the upcoming chapters!)