Cells. Video They Might Be Giants Since every living thing is made of cells, does that mean bigger organisms (like whales or elephants) have bigger cells?

CellsCells

VideoVideo

• They Might Be Giants

How Were Cells Discovered?

How Were Cells Discovered?• New technologies lead to new discoveries

• Robert Hooke - invented the first microscope and was the first to observe and name the small units that make up organisms. He called those small units cells because of the appearance of the structures in the dead cork he observed.



• Anton van Leeuwenhoek - improved the

microscope and procedures for observing cells. He was able to clearly see living cells when observing the scrapings from his teeth.

Fill It In …Fill It In …

Cells observed by …•Hooke:

•Leeuwenhoek:

The Cell TheoryThe Cell Theory

Through the cooperative efforts of many individual scientists, a unifying cell theory developed:

1.All organisms are made of cells

2.Cells are the structural & functional units of organisms

3.Cells come from pre-existing cells

The Cell TheoryThe Cell Theory

Prokaryotic vs Eukaryotic Cells

Prokaryotic vs Eukaryotic Cells

• Are all cells alike?

• Two main types of cells ….

1. Prokaryotic Cells1. Prokaryotic Cells

a.Simplest type of cellb.Includes only bacteria.c.Structure of a

prokaryotic celli. No nucleusii.No membrane-bound

organellesiii.Includes: circular

chromosome (DNA), plasmids (smaller rings of DNA, and ribosomes

Prokaryotic Cells- MYPProkaryotic Cells- MYP

• Thought to have a symbiotic relationship with Eukaryotic Cells• Nucleus• Mitochondria• Chloroplasts

2. Eukaryotic Cells2. Eukaryotic Cells

a. More complex than prokaryotic cells

b. Includes protist cells, fungi cells, plant cells, and animal cells (i.e. - everything EXCEPT bacteria cells)

c. Structure of a eukaryotic celli. Chromosomes contained

within a nucleusii.In addition to ribosomes

contains membrane-bound organelles

Cells :)


Prokaryotic Eukaryotic

Check Yourself!Check Yourself!

1. Who first to observed dead cells?

Who first to observed living cells?

2. What are the two main types of cells?

3. How is the location of the DNA

different in prokaryotic and eukaryotic cells?


1. Who first to observed dead cells? HOOKE

Who first to observed living cells? LEEUWENHOEK




2. What are the two main types of cells?

PROKARYOTIC & EUKARYOTIC




2. What are the two main types of cells? PROKARYOTIC & EUKARYOTIC

3. How is the location of the DNA different in prokaryotic and eukaryotic cells? EUKARYOTIC CELLS KEEP THE DNA INSIDE A NUCLEUS

What do cells share?Structures found in

ALL cells

What do cells share?Structures found in

ALL cells

DNA/Chromosome(s)DNA/Chromosome(s)

1. DNA organized as chromosome(s). DNA directs cell activity

CytoplasmCytoplasm2. Cytoplasm is the “filling” of the cell and is made of up to 90% water. Water provides the necessary environment for all the chemical reactions the cell needs

RibosomesRibosomes3. Ribosomes are

organelles that are the site of protein synthesis. Proteins are essential for enzymes, structure, and communication

• Uses DNA code to synthesize proteins

4. Cell Membrane4. Cell Membrane

•Also called the Plasma Membrane


4 structures found in ALL cells:

1.2.3.4.

Cell MembraneCell Membranea. Composed of a

phospholipid bilayer with embedded proteins. The fluid mosaic model describes the structure of the cell membrane

Cell MembraneCell Membranei. Fluid - individual

phospholipids and proteins can move past each other; they are not fixed in one position

ii.Mosaic - the membrane has more than one type of molecule (phospholipids & proteins)

Cell Membrane- MYPCell Membrane- MYP

• Flexible/strong barrier • Some proteins from channel or pumps to allow things to go in and out of the cell

• Carbohydrates are attached to membrane• These are used as chemical identification markers for the cell

b. Functions of the Cell Membrane

b. Functions of the Cell Membrane

i. Selectively permeable - regulates what enters and leaves the cell. This helps maintain homeostasis

ii.Gives the cell (cytoplasm) shape


The cell membrane is also called …

And is S____________ P_____________

B. Structures (organelles) found in

EUKARYOTIC cells

B. Structures (organelles) found in

EUKARYOTIC cells


Organelle means …

“tiny organ” – specialized structure inside a cell that performs a specific function

1. Nucleus1. Nucleus•Nucleus - surrounds the chromosomes for additional protection; is made of a phospholipid bilayer

Nucleus- MYPNucleus- MYP

• Surrounded by nuclear envelope (lipid bilayer)

• Nuclear pores • Chromatin- DNA bound to proteins

• Chromosomes are condensed chromatin

• Nucleolus- dense region where ribosomes are synthesized

2. Mitochondria2. Mitochondria• Mitochondria - site of cellular respiration which produces cell energy (ATP)• Active cells (muscle) -> hundreds of mitochondria

• Inactive cells (fat) -> few mitochondria

• Structure contains folded membranes which increases surface area allowing more space for more reactions

• (MYP)-inherited through the ovum

•Vacuoles - store food, waste or water to be used inside the cell or excreted from the cell.

•Size differs in plant vs. animal cells• Much, much larger in plant cells … why?

3. Vacuole3. Vacuole

•Lysosomes - contain digestive enzymes which digest food contained in vacuoles as well as old or damaged cell parts• (contain lipid bilayer)

4. Lysosomes4. Lysosomes

5. Endoplasmic Reticulum (ER)5. Endoplasmic Reticulum (ER)

•ER - a series of interconnected folded membranes that function in modifying (changing) proteins, detoxification of alcohols, and communication

ER (MYP)ER (MYP)

• Lipid components of the cell membrane are made here

• Proteins and other material are exported or inserted into the cell membrane

Two Types of ERTwo Types of ER

•Rough ER•Covered in ribosomes

•Modify proteins

Two Types of ERTwo Types of ER

• Smooth ER• Lacks ribosomes

• Detoxification

• Golgi Complex - packages materials for export from cells

• (MYP)- Modify, Sort, and Package • “finishing touches”

6. Golgi Complex6. Golgi Complex

Plant Cellversus

Animal Cell

Plant Cellversus

Animal Cell

1.Chloroplasts - organelles full of chlorophyll that are the site of photosynthesis which produces sugars (C6H12O6)

• Composed of folded membranes for more surface area

Structures found ONLY in plant and plant-like

cells


cells

2. Cell Wall - provides extra support, protection, and shape for the cell

• Found outside the cell membrane and made of cellulose


cells


cells

•Centrioles -organelle that helps with cell division in animal cells

Structure found ONLY in animal cells

Structure found ONLY in animal cells

Cytoskeleton (MYP)Cytoskeleton (MYP)

• Protein filaments to help maintain shape

• May help with movement (amoeba)• Microtubules help with cell division (pulling the chromosomes)


Summary of structure/function:Nucleus -Mitochondria -Vacuole - Lysosome -ER -Golgi -Chloroplast -


Plant only Animal only


1. What four structures are found in all cells?

2. What is the function of the mitochondria?

3. What is the function of the ribosome?

4. What term refers to small cell structures?

5. What two structures are found in plant and plant-like cells?


1. What four structures are found in all cells? DNA, CYTOPLASM, RIBOSOMES, CELL MEMBRANE

2. What is the function of the mitochondria?






2. What is the function of the mitochondria? CELLULAR RESPIRATION/MAKE ENERGY FOR THE CELL







3. What is the function of the ribosome? PROTEIN SYNTHESIS







4. What term refers to small cell structures? ORGANELLES


Check Yourself!Check Yourself!1. What four structures are found in all

cells? DNA, CYTOPLASM, RIBOSOMES, CELL MEMBRANE



4. What term refers to small cell structures? ORGANELLES

5. What two structures are found in plant and plant-like cells? CHLOROPLAST & CELL WALL

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Cells. Video They Might Be Giants Since every living thing is made of cells, does that mean bigger organisms (like whales or elephants) have bigger cells?