CH 6 Outline - 0 Energy Flow in the Life of a Cell Chapter...

Info icon This preview shows pages 1–14. Sign up to view the full content.

Energy Flow in the Life of a Cell Chapter 6 0
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Free Radicals Unbound molecular fragments with the wrong number of electrons Example O2^-1 (should be O2^-2) Highly Reactive Can disrupt structure of molecules “age spots” as you get older is example 0
Image of page 2
These Keep Free Radicals in Check Superoxide dismutase Catalase
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Superoxide Dismutase Catalyzes the formation of hydrogen peroxide from oxygen free radicals and hydrogen ions Accumulation of hydrogen peroxide can be lethal to cells O2^- + 2H^+ -- H2O2
Image of page 4
Catalase Catalyzes the formation of oxygen and water from hydrogen peroxide 2H2O2 ----- 2H2O + O2
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Overall effect… O2^- +H^+ H2O2 H20 +o2 Red molecules = Free radicals = Superoxide dismutase action Pink molecules = Toxic to cells = Catalase action
Image of page 6
Roundworm Experiments Diet supplemented with superoxide dismutase and catalase increased life span of normal worms Diet also allowed worms genetically engineered for susceptibility to free radicals to live normal life span
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

What Is Energy? Energy: Capacity to do work 2 different forms of energy 1. Potential energy (“stored energy”) chemical energy in bonds, electrical charge in a battery, rock at the top of a hill 2. Kinetic Energy (“energy of movement”) Light, heat, electricity, moving objects
Image of page 8
What Can Cells Do with Energy? Energy inputs become coupled to energy-requiring processes Cells use energy for: Chemical work Mechanical work Electrochemical work The Laws of Thermodynamics describe the basic properties of Energy
Image of page 9

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

First Law of Thermodynamics The total amount of energy in the universe remains constant unless energy is added or removed from the system Energy can undergo conversions from one form to another, but it “ cannot be created or destroyed
Image of page 10
One-Way Flow of Energy The sun is life’s primary energy source Producers trap energy from the sun and convert it into chemical bond energy All organisms use the energy stored in the bonds of organic compounds to do work (i.e. the 3 phosphate molecules in ATP can be cleaved off to release Energy)
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Second Law of Thermodynamics Energy conversion is never 100 percent efficient The total amount of energy is flowing from “ high-energy forms to low-energy forms
Image of page 12
Entropy Measure of degree of disorder in a system The living world can resist the flow toward maximum entropy (max.
Image of page 13

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern