Transcript Cell Structure and Function

Cell Structure and Function
The cell is the basic unit of life.
Organelles
• Nucleus
• Largest organelle
• “brains” of the cell
Nucleus
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Nuclear envelope with pores
Chromosomes
Nucleolus
Nucleoplasm
Organelles
• Ribosomes – Protein synthesis
• Endoplasmic reticulum
– Rough – Aids in protein synthesis and has
ribosomes
– Smooth – Aids in lipid and carbohydrate
synthesis; detoxification
Organelles
• Golgi body or Golgi apparatus
• Packages substances to ready them for
export
Organelles
• Lysosomes
Organelles
• Mitochondria
• Power plant of cell
• Produces ATP
Misc. Organelles
• Microtubules – contribute to cytoskeleton
and aid in cell division
• Villi and Microvilli – finger-like extensions
of cell that increase surface area
• Cilia and Flagella – Tiny hairs and “tails”
Cytoplasm
• Cyt = Cell
• Gel-like background of cell
Cell or Plasma Membrane
• Lipid bilayer
• Proteins scattered throughout membrane
• Selectively permeable
Diffusion
• Def: “The net movement of particles from
regions
of high concentration of those particles to
low
concentration”
• This process does not require metabolic
(from the
cell) energy to work.
Osmosis"
• Def: “The net movement of a water
from regions of
high concentration of water to low
concentration,
through a selectively permeable
membrane”
Facilitated Diffusion
• aka Passive transport
• Diffusion ONLY at certain protein carriers
on cell membrane
Active Transport
• Movement against the concentration
gradient
• Requires metabolic energy in the form of
ATP
Cell Metabolism/Cell Respiration
• Acquiring metabolic energy in the form of
ATP
Aerobic Respiration/Metabolism
• Overview
• Glucose + Oxygen >>>>Carbon dioxide +
water + 36 ATP
Glycolysis
• Doesn’t require oxygen
• Occurs in cytoplasm
• Glucose is cleaved into two 3-carbon
molecules
• 2 ATPs generated
Krebs Cycle = Citric Acid Cycle
• Occurs in mitochondria
• 2 ATP generated
• Carbon dioxide released
Electron Transport Chain
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aka respiratory chain
Occurs in mitochondria
Oxygen required
32 additional ATP generated
Anaerobic Metabolism
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Glycolysis; followed by
Lactic acid fermentation
Occurs in the cytoplasm
Only a TOTAL of 2 ATP formed
Not very efficient
Lactic acid accumulation can lead to
muscle soreness
Alcohol Fermentation
• Not in humans!
• Yeast organisms can do this in order to
make alcohol
• Anaerobic pathway
• Glycolysis followed by fermentation
• Releases alcohol and carbon dioxide