Lesson 6B: Additional Organelles and Structures

Mitochondria (cellular respiration)

converts sugars, fats, and other fuels with the help of oxygen to turn into energy for cells

Chloroplasts (photosynthesis)

• converts solar energy into chemical energy

• absorbs sunlight to convert into glucose and water

Mitochondria have ___ membranes

Chloroplasts have ___ membranes

2, 3

Mitochondria and Chloroplasts both contain small amounts of ___ and their own ___

DNA, ribosomes

Mitochondria and Chloroplasts are semiautonomous which means….

they grow and reproduce within the cell independently

What does the mitochondria do?

• site of cellular respiration

• uses oxygen to extract energy from sugars and fats to make ATP

Mitochondria are dynamic because they…

• divide

• change shape

• move around the cell

What are chloroplasts and where are they found?

• site of photosynthesis

• found in plants and algae

Chlorophyll

green pigment in plants which is necessary for capturing light

Chloroplast are also dynamic because they…

• divide

• move around the cell

• change shape

What are peroxisomes?

• single membrane sac

• Contains enzymes that produce hydrogen peroxides (toxic)

• detoxifies alcohol and turns it into water

What does the cytoskeleton do?

network of protein fibers that extend throughout the cytoplasm

• provides cell support

• aids in cell movement 

What 3 fibers are cytoskeleton made of?

microtubules, intermediate filaments, microfilaments

Microtubules

• hollow rods, constructed from tubular, globular protein

• grow by adding tubular dimers

Centrioles

• used in cell division, made up of microtubules

• found only in animal cells

Cilia

• moves substances relevant to the cell (short)

• microtubules extensions from the cell

Flagella

• move the cell itself (long)

• microtubules extensions from the cell

Microfilaments

• solid rods, linear chains of actin(monomer)

• structural roll in cytoskeleton = to bear tension (pulling forces)

Myosin

• motor protein that binds to actin 

• uses ATP to walk across the filament 

• driving force of muscle cells

Nuclear lamina is a ____

intermediate filament

Cell Wall

protective layer external to the plasma membrane of plants, prokaryotes, fungi, and some protists 

Cell Walls in plants, fungi, and bacteria

• cellulose

• chitin

• peptidoglycan

Extracellullar Matrix (ECM)

animals don’t have a cell wall, provides substrate for cells to adhere too

Plasmodesmata

• membrane-lined channels filled with cytoplasm that connect adjacent plant cells

• can move water, ions, and small molecules between cells

3 Cell Junctions in Animals

• Tight junctions

• Desosomes

• Gap junctions

Tight junctions

• bind the adjacent cells together through the interaction of trans-membrane proteins

  • prevent fluid moving between cells

Desosomes

• anchor cells together 

• intermediate filaments bind to desmosomes

Gap junctions

• channels between adjacent cells

• allows water, ions, and small molecules to move between cells