Download 3.2 Cell Organelles

CHAPTER 3 CELLS
3.2 Cell Organelles
KEY CONCEPT Eukaryotic cells share many similarities.
Cells have an internal structure.
• The cytoskeleton has
many functions
• supports and shapes
• cell helps position and
transport organelles
• provides strength
• assists in cell division
• aids in cell movement
• Three main types of fibers
make up the cytoskeleton.
• Microtubules – long hollow tubes
Give cell shape
Act as “tracks” for the
movement of organelles
• Intermediate filaments
Smaller then Microtubules
Give cell strength
• Microfilaments
Smallest of 3
Tiny threads that help cell move
and divide
Recall that Cytoplasm also
helps shape the cell
• Cytoplasm aids in
structure
• The fluid portion mostly
water is called cytosol
• Gives structure to cells
by exerting pressure on
the cell walls of plants
Several organelles are involved in making
and processing proteins.
• Much of the cell is
dedicated to making
proteins
• Recall proteins are made
from 20 amino acids
• Proteins are very
powerful because of
their almost limitless
variety of shapes and
interactions
• Proteins carry out many
critical functions
• Need to be made correctly
• Nucleus
• Control center “brain of cell”
• Stores genetic information - DNA.
• Nucleolus
• Dark spots in nucleus

Ribosomes are made here
• Endoplasmic reticulum
• Interconnected network of thin folded membranes
• Transports materials throughout the cell
• Produce lipids and proteins
Two Types of ER
• Rough ER
• Smooth ER
• Contains ribosomes
• NO ribosomes
• Makes and transports
• Makes and transports
proteins
lipids
• Golgi apparatus
• Closely layered stacks of
membrane enclosed
spaces
• Looks like a stack of
pancakes
• Proteins are sorted,
processed, and delivered
• Packaging and distribution
center of the cell
• Ribosomes
• Ribosomes link amino acids to form proteins.
• Proteins synthesis – they’re made here!
• Vesicles
• Vesicles are membrane-bound sacs that hold and
transport materials.
Other organelles have various functions.
• Mitochondria
• Supply energy to the cell.
• Via respiration – glucose + oxygen = energy
• Vacuoles
• Fluid-filled sacs that hold materials.
• Lysosomes
• Break down worn out cell parts
• Contain enzymes to digest material (bacteria).
• Centrioles
• Centrosomes small regions in
cytoplasm
• Tubes found in the centrosomes.
• Centrioles help divide DNA
• Centrioles form cilia and
flagella
Plant cells differ slightly from animal cells.
•
Plant cells have:
• Cell walls
• Chloroplasts
• Central vacuole
• Cell wall
• Protects, supports and shapes cell
• Made of cellulose – (what is that?)
• Chloroplasts
• Chloroplasts convert solar energy to chemical energy.
 How? Photosynthesis
Magnified
• Food for thought!
• Chloroplast/Mitochondria
• Both have their own DNA and ribosomes
• Were they once separate organisms???????