Post on 22-Jan-2016
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Chapter 3The Cell (part 2)
Golgi complex
• Stacked sacs
• Receive proteins from ER
• Modifies them and packages them up
Lysosomes
• Contain hydrolytic enzymes that:– Bkdn old, worn out, or defective parts
– Digest foreign invaders (e.g., bacteria) engulfed by phagocytosis
– Helps with cell suicide (apoptosis)
Vesicles Ship and Store Cellular Products
• Vesicles: membrane-bound spheres– Used for secretion and storage
– Examples: neurotransmitters, hormones, lysosomes
Figure 3.18
Cytoskeleton Supports the Cell
• Microtubules
• Microfilaments
Mitochondria: Provide Energy to the Cell
• Produce ATP• Contain chromosomes
(DNA) • Evolved from
prokaryote (bacteria-like organism) through symbiosis
Our Cells Use Cellular Respiration to Generate ATP
• Cellular respiration: Cells use glucose and oxygen to synthesize ATP
• Three stages of respiration
– Glycolysis: in cytoplasm
– Citric Acid Cycle: in mitochondria
– Electron Transport System: in mitochondria
Overview of Respiration
• C6H12O6 + O2 CO2 + H2O + ATP
Cellular Respiration
• Glycolysis occurs in the cytoplasm splitting glucose into two pyruvate molecules generating a net gain of two ATP and two NADH molecules
Cellular Respiration
• The transition reaction occurs within the mitochondria. CO2 is removed from each pyruvate forming 2 acetyl CoA molecules
Cellular Respiration
• Electrons are removed from Acetyl CoA in the citric acid cycle releasing two ATP, two FADH2 and six NADH molecules
• CO2 is also released in this process
Cellular Respiration
• The electron transport chain is the final step where the electrons of FADH2 and NADH are transferred from one protein to another, until they reach oxygen
• This process releases energy that results in 32 ATP
Cellular Respiration: An Overview
Brown Fat
Fat fires up. PET/CT scans of a person exposed to cold (left) and at room temperature (right) show the dark signature of brown fat.