Unit 3 (part 1) Study Guide

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

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

Mattias 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 organism
Cytoplasm- jelly-like goo on the inside of the cell
DNA- genetic material
Cell 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 compossed 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 movement
Pilus - small hairlike structures used for attaching to other cells
Capsule - 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
  • chromatin- DNA bound to protein (non-dividing cell)
  • chromosomes-condesed structures seen in dividing cell
  • Also contains an organelle callednucleolus-which makes the cell’s ribosomes
  1. Mitochondria: Energy center or "powerhouse" of the cell. Turns food into useable energy (ATP)
  1. Ribosome- make protein, located on the rough endoplasmic reticulum and throughout the cytoplasm
  1. Golgi Apparatus- processing, packages and secretes proteins; proteins are transported in vesicles
  1. 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
  1. 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 ribosomes
Rough ER - contains ribosomes

  1. 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.
  1. 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.

  1. Chloroplast - Uses sunlight to create food, photosynthesis (only found in plant cells), contains green pigment chlorophyll
  1. Cell Wall - outside the cell membrane of plants and some bacteria, the cell wall serves as support
  1. Central vacuole - large water container, helps maintain a turgor (stiffness) in the plant

Cell Structures and Processes

1.______
2.______
3.______
4.______
5.______
6.______
7.______
8.______
9.______
10.______
11.______
12.______
13.______
14.______
15.______

16. Which organelle contains its own DNA?

17. What is the difference between smooth and rough ER?

A. ______
B. ______
C. ______
D. ______
E. ______
F. ______
G. ______
H. ______
I. ______
J. ______
K. ______
L. ______
M. ______
N. ______

Structures found in plants, but not animal cells:

1. What part of the cell is responsible for breaking down and digesting things?
ribosomes
lysosomes
endoplasmic reticulum
vacuole

2. Identify the organelle pictured.


chloroplast
endoplasmic reticulum
golgi apparatus
mitochondria

3. What part of the cell serves as the intracellular highway?
endoplasmic reticulum
golgi apparatus
cell membrane
mitochondria

4. Which of the following would you NOT find in a bacterial cell?
DNA
cell membrane
golgi apparatus
ribosomes

5. Which of the following is found in plant cells, but not animal cells?
cell wall
vacuole
mitochondria
endoplasmic reticulum

6. The jellylike interior of the cell is called the:
vacuole
cytoplasm
cytoskeleton
nucleus

7. Identify the organelle.


golgi apparatus
endoplasmic reticulum
mitochondria
lysosome

8. What part of the cell makes proteins?
ribosomes
mitochondria
lysosomes
vacuole

9. Where are ribosomes usually located in animal and plant cells?
inside the nucleus
near the cell membrane
on the endoplasmic reticulum
inside the vacuole

10. What part of the cell serves to process, package and export proteins?
mitochondria
endoplasmic reticulum
nucleolus
golgi 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
Cell Membrane
Nucleus
Cytosol
Central Vacuole
Chloroplast
Mitochondrion

Protein Production

The cell is like a factory. Its product is protein which goes to body to serve different functions.

  1. DNA has instructions to build; protein
  2. These instructions are sent to ribosomes
  3. The ribosomes buildprotein and send it throughER
  4. The proteins are delivered to& golgi where they are completed and tagged for export outside the cell

How Proteins are Packaged for Transport

Word Bank

Rough ER / Smooth ER / Nucleus
Golgi Apparatus / Ribosome
Cis face of Golgi Apparatus
Trans face of Gogli Apparatus
Proteins / Transport Vesicle
Cisternae / Nuclear Pore

1. ______
2. ______
3. ______
4. ______
5. ______
6. ______
7. ______
8. ______
9. ______
10. ______
11. ______

Endomembrane System

1. ______
2. ______
3. ______
4. ______
5. ______
6. ______
7. ______
8. ______

Describe the process by which proteins are made and then exported from the cell.