Cell structure and functionCell structure and function

Prokaryotic cells lack nucleus and are the kind of cells that bacteria and archea have.

EukaryoticEukaryotic cells have cells have organelles including a organelles including a nucleus where DNA is nucleus where DNA is located. Protist, fungi, located. Protist, fungi, plants, & animals are plants, & animals are made from eukaryotic made from eukaryotic

cells…cells…

ATP is used by ATP is used by all types of cells all types of cells

as their basic as their basic energy sourceenergy source

Cellular respirationCellular respirationCellular respirationCellular respiration is the process is the process that release energy by breaking that release energy by breaking down glucose and other food down glucose and other food molecules in the presence of oxygen.molecules in the presence of oxygen.There are three steps:There are three steps:– GlycolysisGlycolysis– Kreb’s cycleKreb’s cycle– Electron transport chain Electron transport chain

Cellular respirationCellular respirationHow much energy is present in food?How much energy is present in food?– Quite a lot. One gram of the sugar glucose, Quite a lot. One gram of the sugar glucose,

when burned in the presence of oxygen, when burned in the presence of oxygen, releases 3811 calories of heat energy.releases 3811 calories of heat energy.

– Calorie is the amount of energy needed to Calorie is the amount of energy needed to raise the temperature of one gram of water raise the temperature of one gram of water one degree celcius.one degree celcius.

– This process begins with a pathway called This process begins with a pathway called glycolysis (Greek: sugar splitting).glycolysis (Greek: sugar splitting).

If oxygen is present, then two more steps follow.If oxygen is present, then two more steps follow.If NO oxygen is present, then lactic acid is madeIf NO oxygen is present, then lactic acid is made

– This is why muscles hurt during extraneous workouts.This is why muscles hurt during extraneous workouts.

How efficient is cellular respiration?How efficient is cellular respiration?The 36 ATP molecules the cell makes per The 36 ATP molecules the cell makes per glucose represent about 38% of the total glucose represent about 38% of the total energy of glucose.energy of glucose.

That might not seem like much, but it That might not seem like much, but it means that the cell is actually more means that the cell is actually more efficient at using food than the engine of a efficient at using food than the engine of a typical automobile.typical automobile.

What happens to the remaining 62%?What happens to the remaining 62%?– It is released as heat, which is one of the main It is released as heat, which is one of the main

reasons why we are warm to the tough – reasons why we are warm to the tough – especially after working-out. especially after working-out.

Questions?Questions?