Cell Notes Chapter 4

4.1 Vocabulary

• Cells –

• Cell Theory –

• Surface-To-Volume Ratio –

• Cytoplasm -

4.1 Cell Theory: Schleiden, Schwann and Virchow

• 1) All cells come from pre-existing cells.• 2) Cells are the smallest unit of living

organisms. (Cells are the basic units of life)• 3) All living organisms are made up of one or

more cells.

4.1 Why are cells so small?

• Larger cells do not function as efficiently. • Center of the cell = “Command Center”– Nucleus– DNA• The longer it takes to reach the “Command Center”,

the longer life processes take

• See figure 4.2 on page 71 in textbook– As the cell radius increases, the volume increases

proportionally. Volume is directly proportional to surface area!

4.1 Shape –vs- Function

• All cells have unique shapes which are not random, but instead serve specific functions.

• Altering the shape of a cell can alter its ability to function well.

• Ex: Why must blood cells take their shape?• Why must neurons have their shape?

4.1 Why must blood cells take their shape? Neurons?

4.1 Sum It Up!

• All living things are composed of one or more cells, each a small volume of cytoplasm surrounded by a cell membrane. Most cells and their components are so small they can only be viewed using microscopes.

4.2 Vocabulary

• Fluid mosaic model –

• Lipid Bilayer –

• Proteins within the Membrane – – Membrane proteins – – Cell surface proteins – – Transmembrane proteins -

Figure 4.6 – page 75 Proteins are embedded within the lipid bilayer

4.2 Sum It Up!

• All cells are encased within a delicate lipid bilayer sheet, the plasma membrane, within which are embedded a variety of proteins that act as markers or channels through the membrane.

4.3 Vocabulary

• Prokaryotes – • Organelles –

– Explain the DNA of a prokaryotic cell.

– Explain what a prokaryotic flagellum is used for.

– Do Prokaryotes have organelles?

Prokaryotes

• Single cells only• Limited parts (ribosome, cell membrane, cell

wall)• No specific compartments to perform key

metabolic functions• Oldest cells on the earth• Example: Bacteria

Prokaryotes vs Eukaryotes

•

4.3 Sum It Up!

• Prokaryotic cells lack a nucleus and do not have an extensive system of interior membranes.

4.4 Vocabulary- Organelles –

- Nucleus – - Chromosomes -

- Eukaryotes – - Plant Cells (internet search)– - Animal Cells (internet search)– - Protista (internet search)-

- Cytoskeleton - - Cell Walls -

4.4 Eukaryotes

• Single AND multicellular• Multiple organelles• Organelles serve as compartments for specific

metabolic functions• Younger cells• Ex: Plant and animal cells, protista

4.4 Sum It Up!

• Eukaryotic cells have a system of interior membranes and membrane-bound organelles that subdivide the interior into functional compartments.

FYI

• Kingdom Protista

4.5 Vocab• Nucleus – • Nuclear Envelope – • Nuclear Pores – • Chromosomes – • Chromatin – • Ribosome - • rRNA – • Nucleolus - • Endoplasmic Reticulum – • Plasma Membrane – • Golgi Complex (Apparatus) –• Lysosomes – • Mitochondria – • Chloroplast –

4.5 – The Nucleus • Nucleus – Command

center of the cell storing all genetic and hereditary information

• MAKES PROTEINS• Nuclear envelope – two

membranes • Nuclear pore – allows

passage of RNA• Ribosomes – read RNA

copy of a gene to direct proteins

Plant Cells

• All living things which conduct photosynthesis

• Eukaryotic• Cell Wall• Chloroplast• Vacuole

Animal Cells

• Eukaryotic• NO chloroplast• No Cell wall

Venn Diagram

• Plant Cell• Animal Cell• Prokaryotic Cell

4.5 Sum It Up!

• The nucleus is the command center of the cell, issuing instructions that control cell activities. It also stores the cell’s hereditary information.

4.6 Vocabulary

• Endoplasmic Reticulum (ER) – – Rough ER - – Smooth ER -

• Golgi Bodies (Complex) – • Lysosomes –

4.6 Endomembrane SystemEndoplasmic Reticulum

• Rough ER - Cell makes protein to leave the cell

• Smooth ER – cell makes carbohydrates & lipids

4.6 Golgi Complex

• “Post office” of the cell• Collection, packaging,

and distribution of molecules made by the cell.

4.6 Lysosomes

• From the Golgi Complex• Contain Enzymes• Break down & destroy

“trash” from cells or the cell themselves.

4.6 Sum It Up!

• An extensive system of interior membranes organizes the interior of the cell into functional compartments that manufacture and deliver proteins and carry out a variety of specialized chemical processes.

4.7 Vocab

• Mitochondria –

• Chloroplast -

4.7 Organelles with DNA

• Mitochondria– ENERGY – how the cells

get energy from food!• 2 membranes• Cristae• Matrix!

• Chloroplast– ENERGY - Photosynthesis

in plants and algae• Thylakoids – light

powered reactions take place

4.7 Sum It Up!

• Eukaryotic cells contain several complex organelles that have their own DNA and are thought to have arisen by endosymbiosis from ancient bacteria.

4.8 Vocab

• Cytoskeleton – 3 types of Protein Fibers: 1. Microfilaments – 2. Microtubules – 3. Intermediate filaments - • Centrioles – • Vacuoles -

4.8 Cytoskeleton• Responsible for the movement of a cell:– Modification of the shape of a cell– Modification of the size/location of a cell– Modification of the rigidity of a cell

• Intermediate filaments – overlapping proteins provides strength to the cell

• Microtubules – composed of tubulin proteins – intracellular transportation and stabilization of cell structure

• Actin microfilaments – 2 strands of the protein actin twist together to form bundles – this allows the cell to move.

4.8 Cytoskeleton

• Centrioles – occur in pairs and located at right angles to one another near nuclear envelope.

• Vacuole – contains water, sugar, ions, and pigments. “storage”

4.8 Sum It Up!

• The cytoskeleton is a latticework of protein fibers that determines a cell’s shape and anchors organelles to particular locations within the cytoplasm. Cells can move by changing their shape.

Whiteboard: Number your Diagram!SHOW & Explain THE FUNCTION OF THE FOLLOWING:

• Plant Cell1. Eukaryotic2. Cell Wall3. ER4. Nucleus5. Golgi Complex6. Mitochondria7. Chloroplast8. Chromosomes9. Nucleolus10.Ribosomes11.Vacuole

• Animal Cell1. Eukaryotic2. Cell Membrane3. ER4. Nucleus5. Golgi Complex6. Mitochondria7. Chromosomes8. Nucleolus9. Ribosomes