Mitochondria, Chloroplasts, & Cytoskeleton

Lecture 13

Mitochondria (structure)

• double membrane (outer/inner)

• intermembrane space

• mitochondrial matrix

• DNA

• ribosomes

Mitochondria (function)

cellular respiration: converts oxygen and nutrients into ATP

*FOR ANIMALS*

Chloroplasts (structure)

• double membrane (outer/inner)

• granum: stacks on thylakoids

• stroma: fluid surrounding the stacks

• chlorophyll

• DNA

Chloroplasts (function)

site of photosynthesis for plants and algae; produces glucose and oxygen from CO2 and H2O

*FOR PLANTS*

Endosymbiont Theory

evolutionary theory; similarities in the mitochondria and chloroplasts suggest that eukaryotic cells evolved through symbiotic relationships among prokaryotes

Cytoskeleton (structure)

network of fibers throughout the cytoplasm

Cytoskeleton (function)

• maintains cell shape

• provides anchorage for organelles

• aids in intracellular transport

• interacts with motor proteins

Microtubules

largest part of the cytoskeleton

• made of tubulin dimers

• guides movement

• separates chromosomes

• has centrosomes that contain centrioles

• has cilia & flagella used for locomotion

Microfilaments

smallest part of the cytoskeleton

• made of actin

• resists pulling

• movement and muscle contraction

• drives the movement of cytoplasm in plants

• supports microvilli

Intermediate Filaments

middle-sized part of the cytoskeleton

• made of various fibrous proteins

• reinforces cell shape

• anchors organelles

• mechanical strength

• more permanent