Unit 3 (part 1) Study Guide (ANSWERS)

Objectives: Can you….?

List the scientists who contributed to our knowledge of the cell

List the 3 components of the cell theory

Compare prokaryote to eukaryote cells

Label a plant and animal cell

Describe the functions of all cell organelles

Early Contributions:

Robert Hooke - The first person to see cells, he was looking at cork and noted that he saw "a great many boxes. (1665)

Anton van Leeuwenhoek - Observed living cells in pond water, which he called "animalcules" (1673)

Theodore Schwann - zoologist who observed that the tissues of animals had cells (1839)

Matthias Schleiden - botonist, observed that the tissues of plants contained cells (1845)

Rudolf Virchow - also reported that every living thing is made of up vital units, known as cells. He also predicted that cells come from other cells. (1850)

The Cell Theory:

1. Every living organism is made of one or more cells.2. The cell is the basic unit of structure and function.3. All cells arise from pre-existing cells.

Cell Features: (All cells have these characteristics)

Ribosomes - make protein for use by the organismCytoplasm - jelly-like goo on the inside of the cellDNA - genetic materialCell membrane - outer boundary of the cell, some stuff can cross the cell membrane.

CELL MEMBRANE (or plasma membrane)

The cell membrane is semi-permeable (selectively permeable). It is composed of a double layer of phospholipids with embedded proteins

Jobs of the cell membrane

Isolate the cytoplasm from the external environment Regulate what comes in and what goes out.

Communicate with other cells

Phospholipids (fats) contain a hydrophilic head and a nonpolar hydrophobic tail, which creates a barrier.

Prokaryotic Cells

Prokaryotes are very simple cells, probably first to inhabit the earth. They are always single celled organisms. They have a cell wall.

Prokaryotic cells do not contain a nucleus. Their DNA is floating in the cytoplasm in a circular loop called a nucleoid.

Bacteria are prokaryotes. 

Label the Bacteria

The word "prokaryote" means "before the nucleus"

Other features found in some bacteria:

Flagella - used for movementPilus - small hair like structures used for attaching to other cellsCapsule - tough outer layer that protects bacteria, often associated with harmful bacteria

Eukaryotic Cells (Plant and Animal Cells)

Eukaryotic cells are more advanced cells. These cells are found in plants, animals, and protists (small unicellular "animalcules").

The eukaryotic cell is composed of 4 main parts:

Cell membrane - outer boundary of the cell

Cytoplasm - jelly-like fluid interior of the cell

Nucleus - the "control center" of the cell, contains the cell's DNA (chromosomes)

Organelles - "little organs" that carry out cell functions

Cell Structures - Organelles

1. The Nucleus

Usually found at center of cell

Has a nuclear membrane which contains nuclear pores

 Contains cell's DNA in one of 2 forms

o chromatin- DNA bound to protein (non-dividing cell)

o chromosomes- condensed structures seen in dividing cell

 Also contains an organelle called nucleolus - which makes the cell’s ribosomes

 

2. Mitochondria: Energy center or "powerhouse" of the cell. Turns food into useable energy (ATP)

3. Ribosome - make protein, located on the rough endoplasmic reticulum and throughout the cytoplasm

4. Golgi Apparatus - processing, packages and secretes proteins; proteins are transported in vesicles

 

5. Lysosome - contains digestive enzymes that can break things down, also called a "suicide sac" because the rupturing of the lysosome will cause the cell to destroy itself

6. Endoplasmic Reticulum - Transport, "intracellular highway". Ribosomes are positioned along the rough ER, protein made by the ribosomes enter the ER for transport.

Smooth ER - no ribosomesRough ER - contains ribosomes

7. Cytoskeleton - helps maintain the cells shape; supports the cell and aids in cell movement. It is composed of microtubules which are made by the centrioles.

8. Vacuole - storage area for water and other substances, plant cells usually have a large central vacuole

Plant Cell: Has all the components of animal cells with some additional structures.

9. Chloroplast - Uses sunlight to create food, photosynthesis (only found in plant cells), contains green pigment chlorophyll

10.Cell Wall - outside the cell membrane of plants and some bacteria, the cell wall serves as support

11.Central vacuole - large water container, helps maintain a turgor (stiffness) in the plant

Cell Structures and Processes1. _____Mitochondria________________2. ______Centrioles_______________3.__Lysosomes___________4. ____Cytoplasm_________5. ________Nucleolus______6. Nuclear Membrane

7. _____Chromosomes_8. ____Flagella____9. Rough ER___10. _____Golgi Apparatus 11. ___Microtubules______12. _GolgiBodies/Vesicle____13. ___Ribososmes_____14. ___Smooth ER______15. ___Cell Membrane_____

16. Which organelle contains its own DNA? Mitochondria

17. What is the difference between smooth and rough ER? Rough ER – Contains ribosomes and makes proteins/lipids; smooth ER makes and distributes products (calcium); also detoxifies poisons

A. ____Nucleus________B. ____Chromosomes___________C. ___Nucleolus ___________D. ___ Nuclear membrane _________E. _____Rough ER________F. _____Smooth ER_____________G. _____Vacuole_____________H. ______Microtubules/Cytoplasm______I. _____Chloroplasts______J. ______Cell Wall_________K. _______Cell Membrane___________L. ____Mitochondria__________M. ____Vesicle/Golgi Body___________N. ______Golgi Apparatus_________

Structures found in plants, but not animal cells: Cell Wall, Chloroplasts, Large Central Vacuole

1. What part of the cell is responsible for breaking down and digesting things?ribosomeslysosomesendoplasmic reticulumvacuole

2. Identify the organelle pictured.

chloroplastendoplasmic reticulum golgi apparatusmitochondria

3. What part of the cell serves as the intracellular highway?endoplasmic reticulumgolgi apparatuscell membranemitochondria

4. Which of the following would you NOT find in a bacterial cell?DNAcell membranegolgi apparatusribosomes

5. Which of the following is found in plant cells, but not animal cells?cell wallvacuolemitochondriaendoplasmic reticulum

6. The jellylike interior of the cell is called the:vacuolecytoplasmcytoskeleton nucleus

7. Identify the organelle.

golgi apparatusendoplasmic reticulummitochondrialysosome

8. What part of the cell makes proteins?ribosomesmitochondrialysosomes vacuole

9. Where are ribosomes usually located in animal and plant cells?inside the nucleusnear the cell membraneon the endoplasmic reticuluminside the vacuole

10. What part of the cell serves to process, package and export proteins?mitochondriaendoplasmic reticulum

nucleolusgolgi apparatus

Comparing Cells

Use what you know about each type of cell (reference pictures if needed), and place a check in the box if the cell has that characteristic or structure.

  Bacteria Plant Animal

Cell Wall  x  x  

Cell Membrane  x  x  x

Nucleus    x  x

Cytosol  x  x  x

Central Vacuole    x  

Chloroplast    x  

Mitochondrion    x  x

Protein Production(JUST A LITTLE EXTRA)The cell is like a factory. Its product is protein which goes to body to serve different functions.

1. DNA has instructions to build; protein2. These instructions are sent to ribosomes

3. The ribosomes build protein and send it through ER

4. The proteins are delivered to& golgi where they are completed and tagged for export outside the cell