Cell Structure and Function

KWL - The Cell

What do you

know

?

What do you

want

to know?

What have you

learned

?

Explore Cells

 At your assigned lab table, draw the slide that you observe under the microscope.

 Write down any interesting details you would use to describe the slide.

 Be prepared to share your findings with the group.

Human Epidermis – Animal cells

Staphylococcus epidermis

Cardiac (heart) Muscle

Stems

Leaves

Amoeba proteus

Root tip

 What are some similarities and differences that you observed by looking at a variety of cells?

Explain: Cells

History of the cell

 In 1665, Robert Hooke was the first to view cells from cork (dead plant material). He called them “cells” because they looked like tiny rooms.



Anton van Leeuwenhoek

saw tiny living organisms in water in 1675.

 In 1838, Matthias Schleiden determined that plants are made up of cells.

 In 1839, Theodor Schwann determined that animals are made up of cells.

 In 1855, Rudolf Virchow concluded that new cells are produced from the division of existing cells.

The Cell Theory

 All living things are composed of cells.

 Cells are the basic units of structure and function in living things.

 New cells are produced from existing cells.

Types of Cells

 Two kinds of cells depending on whether they have a nucleus

Eukaryote Prokaryote Genetic material

Prokaryotes

 Usually small and simple  Genetic material (DNA) is not contained in a nucleus  The ONLY prokaryotes in the world are BACTERIA.

Prokaryotic Cells

Eukaryotes

    Usually larger and more complex than prokaryotes.

May be unicellular like an amoeba or multicellular like a plant Contain dozens of specialized structures called organelles.

Includes protists, fungi, plants and animals.

Eukaryotic cell structure

 Two major parts:  Nucleus  Cytoplasm-portion of the cell outside the nucleus

Eukaryotic cells

Nucleus-The control center

 Function:  Contains almost all of the cell’s DNA for coding proteins and other molecules.

 DNA is found on chromosomes which contain genetic information.

Nucleus-The control center



Structure:

 Surrounded by a double membrane called a nuclear envelope. It is dotted with many pores (holes) to allow materials (RNA, proteins, etc) in and out of the nucleus.

 Small internal region called a nucleolus where ribosomes are made.

Ribosomes



Function:

 Site of protein assembly.



Structure:

 Small pieces of RNA and protein found throughout the cell.

Endoplasmic Reticulum



Function:

 Site where lipid parts of cell membrane are made, along with proteins and other materials to export from the cell.



Structure:

  Rough ER- has ribosomes on surface to assemble proteins Smooth ER-NO ribosomes on surface

Golgi Apparatus

  Function:  Modify, sort, and package proteins and other materials from the ER for storage in the cell or release from the cell. It puts the finishing touches on proteins.

Structure:  Stack of closely packed membranes

 You have 3 minutes to compare your notes with a neighbor. Be sure to ask questions and fill in any blanks you may have in your notes at this time.

Lysosomes-The Clean Up Crew

 

Function:

 Breakdown of lipids, carbohydrates and proteins into small molecules to be used by the rest of the cell   Breakdown used up organelles Get rid of all “stuff” in the cell

Structure:

 Small, filled with enzymes

Vacuoles - Storage

 

Function:

 Stores water, salts, proteins and carbohydrates

Structure:

 Sac-like  Plant cells have one large central vacuole  Animal cells have many small vacuoles

Mitochondria - Energy



Function:

 Convert chemical energy in food into materials easier for the cell to 

Structure:

 Enclosed by two  membranes with the up.

Contains it’s own DNA (unlike other organelles) mother’s!

Chloroplasts – Energy in Plants

 

Function:

 Captures energy from the sun (solar energy) and changes it into food (chemical energy) for plants (photosynthesis)

Structure:

 Surrounded by two membranes    Contains own genetic information like mitochondria Contains green pigment called chlorophyll

Not found in animal cells!

 With your neighbor, list similarities and differences between mitochondria and chloroplasts. Be prepared to share with the class.

Cytoskeleton- structure and support  

Function:

 Helps maintain cell shape  Helps with movement of the cell (i.e. flagella and cilia)

Structure:

 Two types: microfilaments and microtubules

Cell Membrane

 

Function:

  Regulates what enters and leaves the cell Provides protection and support

Structure:

  Double membrane called a lipid bilayer Flexible structure that forms a strong barrier between the cell and its surroundings

Cell Wall

 

Function:

 Provides support and protection for the cell

Structure:

 Lies outside the cell membrane  Found in plants, algae, fungi and many bacteria 

NOT FOUND IN ANIMAL CELLS!

 Individually, write down 3 differences between plant and animal cells.

KWL - The Cell: Your ticket out the door What do you

know

?

What do you

want

to know?

1. Circle information that you heard in today’s notes 2. Asterik (*) next to questions you had answered today What have you

learned

?

3. Add new information learned