Chapter 7:Cell Structure and
Function
Sec7.1: Cell theory and cell types
Do Now
• In about 4-5 sentences, discuss the relationship between structure
and function; use the examples of petals and/or sepals to support
your discussion.
• Read the article provided in your notes packet and answer the
questions that follow.
A. The discovery of cells
1. Invention of the microscope (around 1590) was important to the
discovery of cells
2. 1665 ~ Robert Hooke publishes the first drawings of cells
3.1674 ~ Anton van Leeuenhoek found organisms in pond
water
4.1838 ~ Matthias Schleiden concluded that all plants are
made of cells
5. 1839 ~ Theodore Schwann concluded that all animals
are made of cells.
6.1855 ~ Rudolf Virchow concludes that all cells come
from pre-existing cells
B. Cell Theory
1. Discoveries in the 1600’s through the 1800’s led to the
development of Cell Theory.
2. Three components of cell theory:
a. All living things are composed of cells
b. Cells are the basic unit of structure and function in living things
c. All cells come from preexisting cells
Inquiry Activity
• “All new cells arise from existing ones”.
In your pairs, discuss and answer the following questions:
1. What characteristics of life are enumerated through this statement?
2. Why is it important for new cells to arise from existing ones?
C. Two Major groups of cells = Prokaryotic and
Eukaryotic cells.
1.Prokaryotic Cells
2.Eukaryotic Cells
a. Simple, single celled organisms whose DNA is NOT a. Complex cells whose DNA is stored in a nucleus.
stored in a nucleus
b. Do not have a nucleus and lack organelles that are
surrounded by membranes
c. Tiny ~ much smaller than eukaryotic cells
d. Internal Structure is very simple
e. Example = bacteria
b. Have a nucleus and several other organelles that are
surrounded by membranes.
c. Larger than prokaryotic cells
d. Complex internal structure
e. Can be single celled or part of a multicellular organism
f. Examples:
i. Plants and animals (multicellular)
ii. Protists = single celled eukaryotes
•Ex. = Amoeba, paramecium, euglena
D. Viruses
1.Particles made of nucleic acids and proteins that reproduce by
infecting living cells
a. Are viruses living???
Closure Activity
• Write down, in complete sentences, three things you learnt today.
Animal Cell Vs. Plant Cell
Inquiry Activity
• Compare and contrast an animal cell and a plant cell using a Venn
Diagram.
Plasma Membrane
• Plasma Membrane is also known as cell membrane.
• Plasma membrane are made of a phospholipid bilayer that is
embedded with proteins.
• Plasma membrane acts as a selective barrier that allows only certain
material to enter or leave the cells.
Analogy:
Nucleus
• The function of the nucleus is to house all of the cell’s genetic
material.
• The nucleus is made of a nuclear envelope (an outer membrane) that
protects the nucleus.
• The nucleolus is the inner fluid that makes up the nucleus.
Analogy:
Cytoplasm
• Is the region between the plasma membrane and the nucleus.
• It ensures smooth transportation of material inside the cell. It also
helps in providing structure for the cell.
• Analogy:
Cell Wall
• Cell wall is the outermost membrane of plant cells, algae and fungi.
• Cell walls are made of a tough carbohydrate fiber known as
cellulose- The cellulose result in strong and rigid cells.
• Cell walls are also made of pores that allow for essentials to pass
through.
• All in all the cell wall protects and supports the cell. Analogy:
Looking at the picture above, what can you deduce about the
functions of cell wall? Explain in about 2-3 sentences.
Ribosomes
• Ribosomes are small particles of RNA and proteins.
• Their job is to manufacture proteins.
Analogy:
Rough ER
• Rough ER are packed with ribosomes and are found close to the
nucleus.
• Their job is to make fats (lipids) and proteins and to store the
proteins.
• Analogy:
Smooth ER
• Smooth ER are found close to nucleus are not covered with
ribosomes.
• Their job is to make lipids, store proteins and detoxify the cells.
Analogy:
Inquiry Activity
• The job of the liver is to detoxify chemicals. Based on this function
which organelle is found in abundance in the cells of the liver? Justify.
Golgi Bodies
• The golgi bodies are made of many membranes stacked up together.
They look very similar to the ER.
• Their job is to package and modify the proteins from the ER, to deliver
them to the various different destinations inside and outside the cell.
Analogy:
Vacuole
• Vacuoles are large saclike structures that are found in plant cells.
• Their job is to store, water and food.
Analogy:
Lysosome
• Lysosomes are small circular organelles that are packed with
enzymes.
• Their job is to breakdown food and decompose dead matter. Analogy:
Chloroplast
• Chloroplast are found in plant cells and are organelles that are
stacked with chlorophyll.
• The job of the chloroplast is to trap sunlight and water to
manufacture food for the plant in a process called photosynthesis.
• The compartmentalization of the chloroplast allows for efficient
synthesis of carbohydrates.
Analogy:
Mitochondria
• Mitochondria is known as the powerhouse of the cell
• It is found in all eukaryotic cells
• The function of the mitochondria is to produce energy.
• The compartmentalization of mitochondria allows for efficient
production of energy. Analogy:
Closure activity
• http://www.pbslearningmedia.org/resource/tdc02.sci.life.cell.organel
les/organelles-in-the-cytoplasm/