NaNa++/K/K+ + Pumps and Pumps and Beginning of Ch 8Beginning of Ch 8

NaNa++/K/K++ ATPase Pumps ATPase Pumps

Pumps NaPumps Na++ OUT OUT of cellof cell Pumps KPumps K++ ININ to cell to cell Requires energy Requires energy Pumps ions against their concentration Pumps ions against their concentration

gradientgradient

Because NaBecause Na++/K/K++ pumps create a pumps create a concentration gradient of Naconcentration gradient of Na++ outside of outside of the cell, the flow of Nathe cell, the flow of Na+ + back INTO the cell back INTO the cell can be coupled with a sugar molecule, can be coupled with a sugar molecule, essentially giving the sugar molecule a essentially giving the sugar molecule a free ride into the cell. free ride into the cell.

This is called This is called coupled transport coupled transport

Sodium potassium pumpSodium potassium pump

http://www.youtube.com/watch?v=SByeThttp://www.youtube.com/watch?v=SByeTZKAR1Q&feature=relatedZKAR1Q&feature=related

CHAPTER 8: CHAPTER 8: Cellular EnergyCellular Energy

Transformation of EnergyTransformation of Energy

11stst Law of Thermodynamics: Law of Thermodynamics: The Law The Law of Conservation of Energyof Conservation of Energy

Energy is never created nor destroyed; it Energy is never created nor destroyed; it merely changes form. merely changes form.

- Rudolf Claussius- Rudolf Claussius

22ndnd Law of Thermodynamics: Law of Thermodynamics:

Energy cannot change form without losing Energy cannot change form without losing some of the useable energysome of the useable energy This is in part because of the natural tendency of This is in part because of the natural tendency of

all systems to move toward chaos, or increase in all systems to move toward chaos, or increase in entropyentropy. .

Autotrophs vs. HeterotrophsAutotrophs vs. Heterotrophs

Auto – Gr. “self”Auto – Gr. “self” Hetero – Gr. “other” Hetero – Gr. “other” Troph – Gr. “eating”Troph – Gr. “eating”

Autotrophs make their own foodAutotrophs make their own food Chemoautotroph – from chemical Chemoautotroph – from chemical

compoundscompounds Photoautotroph – from lightPhotoautotroph – from light

Heterotrophs get food from outside Heterotrophs get food from outside sourcessources We are heterotrophsWe are heterotrophs

MetabolismMetabolism

ALL of the chemical reactions in a cellALL of the chemical reactions in a cell Many reactions in cells are connected Many reactions in cells are connected

together and these are called “metabolic together and these are called “metabolic pathways” pathways”

Two types of metabolic pathway:Two types of metabolic pathway: Catabolic – release energy by breaking down Catabolic – release energy by breaking down

large moleculeslarge molecules Anabolic – use energy from catabolism to make Anabolic – use energy from catabolism to make

larger moleculeslarger molecules

PhotosynthesisPhotosynthesis

An An anabolic anabolic pathway pathway Light energy from the sun is harnessed and Light energy from the sun is harnessed and

converted into chemical energy converted into chemical energy Plants use light, COPlants use light, CO22, and water to make , and water to make

sugars and Osugars and O22

Cellular RespirationCellular Respiration

A A catabolic catabolic pathway that uses organic pathway that uses organic molecules (like food) to break down into molecules (like food) to break down into energy that will be used by the cell energy that will be used by the cell Uses OUses O22 to break down molecules, to break down molecules,

byproducts include CObyproducts include CO2 2 and water and water

Again:Again:

Photosynthesis Photosynthesis Uses COUses CO2 2 , light, and water and makes sugar, light, and water and makes sugar

Cellular respirationCellular respiration Uses organic molecules (like sugar) and OUses organic molecules (like sugar) and O22

and produces COand produces CO2 2 and waterand water

ATP – Adenosine triphosphateATP – Adenosine triphosphate

The most important source of chemical The most important source of chemical energy energy

It is an energy-carrying moleculeIt is an energy-carrying molecule Found in all types of organismsFound in all types of organisms Releases energy when it loses a Releases energy when it loses a

phosphate group phosphate group becomes A becomes ADDPP