Chapter 3

The 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.