CHAPTER 7 –CELL STRUCTURE AND FUNCTION

Can anyone explain what “life is cellular” means?

7-1 Life is Cellular

Discovery of the cell

Robert Hooke The study of cells is

known as cytology. Cytology began in 1665,

when Robert Hooke, an English scientist, first glimpsed into the microscopic world of cells by examining dead cork cells

All Hooke was able to observe were the thick walls that surrounded each cell.

Theorize how Mr. Hooke came up with the name of “cells”

Discovery of the cell

Anton Van Leeuwenhoek - 1674

Observed living organisms in pond water

Cell Pioneers – Cell Theory

During the next 170 years, other scientists used microscopes to further advance their knowledge of cells.

Matthias Schleiden - 1838 Concluded that all plants are made of

cells

Theodore Schwann – 1839 Concluded that all animals are made of

cells

Rudolph Virchow - 1858 Said that cells come from 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.

2 Basic Types of Cells Prokaryotes (prokaryotic cells)

Does have – DNA, cell wall, cytoplasm and ribosomes

DO NOT have - a Nucleus, Membrane bound organelles

Examples: bacteria Eukaryotes (eukaryotic cells)

Cells that DO have a nucleus and other organelles

Examples: plant cells and animal cells

Prokaryotes:-No nucleus

-no membrane bound organelles

-bacteria

Both:-cell wall

-cytoplasm-ribosomes

-DNA

Eukaryotes:-nucleus

-membrane bound organelles

-plants/animals/fungi/protists

Identify What kind of cell

Identify What kind of cells

Identify What kind of cell

Identify What kind of cell

CELL STRUCTURES

Chapter 7Sections 1 & 2

Cell Structures Specialized structures that perform specific functions in

the cell are called organelles.

Organelle means “little organ”.

Example how to take notes:

1 – Name: Cell Wall

2 - Picture – this should be an illustration that shows what the structure does; what is the function of the structure? NOT a picture straight from textbook.

3 - Description of the picture that you came up with; Example: Rigid wall that surrounds the cell.

4 – Function - How does your picture connect to the function of the cell part? Example: the cell wall protects and supports the cell. It also helps control what comes in and out

5 - Type - Plant or Animal cell; Prokaryote or Eukaryote; Example: found in all prokaryotes, fungi and, plant cells; NOT found in animal cells!!!

Cell Membrane

Physical Description: thin, flexible barrier around the cell (just inside the cell wall OR the outside border of animal cells)

Function: controls what enters and leaves the cell; selectively permeable; support and protection

Type of Cell: found in all cells

Analogy: it is like the Shipping/receiving department of a factory

Monday 1/30

Explain the differences between eukaryotes and prokaryotes.

Identify the organelle that acts as the “Shipping/receiving department ” of the cell

 

Prokaryotes:-No nucleus

-no membrane bound organelles

-bacteria

Both:-cell wall

-cytoplasm-ribosomes

-DNA

Eukaryotes:-nucleus

-membrane bound organelles

-plants/animals/fungi/protists

Monday 1/30

Explain the differences between eukaryotes and prokaryotes.

Identify the organelle that acts as the “Shipping/receiving department ” of the cell

Cell Membrane

Cytoplasm Physical Description: the fluid-like material

inside the cell membrane

Function: contains the organelles; “cell jelly” Site for chemical reactions

Type of Cell: found in all cells

Analogy: it is like the air of a factory

Nucleus

Physical Description: large organelle that is usually near the center; contains the cell’s genetic material (DNA)

Function: Controls the cells activities

Type of Cell: found in eukaryotes

Analogy: it is like the boss of a factory

Nuclear Membrane (aka Nuclear Envelope)

Physical Description: double layered membrane that surrounds the nucleus; has pores

Function: Protects the nucleus; pores allow material in and out of the nucleus.

Type of Cell: found in eukaryotes

Analogy: it is like the office of a factory

Nucleolus Physical Description: small, dense region in the

center of the nucleus

Function: produces ribosomes

Type of Cell: found in eukaryotes

Analogy: it is personnel department (the people who hire workers) for a factory

Cytoplasm

Identify What organelle is called the “air of the factory.” Site for chemical reactions

Cell wall

Identify What organelle protects and supports the cell. Not found in animal cells

Nucleolus

Identify What organelle Produces ribosomes; It is sometimes called the “Personnel” department of the cell

Ribosomes Physical Description: very small, round

structures either attached to the endoplasmic reticulum or free (floating in the cytoplasm)

Function: makes proteins

Type of Cell: found in all CELLS

Analogy: it is like the workers in a factory

Endoplasmic Reticulum (ER) Physical Description: internal membrane system

2 Types: Rough—has ribosomes Smooth—NO ribosomes

Function: Rough—modifies proteins Smooth—assembles components of the cell

membrane Type of Cell: found in eukaryotes

Analogy: it is like the assembly line of a factory

Tuesday 1/31

Get a folder from Mr. Rogers’ Desk

Put your name on the front right corner and wait for instruction 

Golgi Apparatus (aka Golgi Body) Physical Description: stack of membranes in the

cytoplasm

Function: attaches carbohydrates and lipids to proteins; gives proteins the “address” of their final destination

Type of Cell: found in eukaryotes

Analogy: it is like the mailroom or packaging department of a factory

Lysosome Physical Description: small, round sacks in the

cytoplasm

Function: breaks down lipids, carbohydrates, and proteins into useable molecules; break down old or damaged organelles

Type of Cell: found in all eukaryotes BUT are very rare in plant cells

Analogy: it is like the janitor/maintenance crew of a factory

Vacuole / Vesicle Physical Description: large, spacious sack in the

cytoplasm

Function: stores materials for the cell (water, food, waste, etc…)

Type of Cell: found in all eukaryotes (usually one large vacuole in plants and many small vacuoles in animals)

Analogy: it is like the storage closet of a factory

Mitochondria

Physical Description: “bean-shaped” organelle that has a folded inner membrane (called cristae)

Function: use FOOD to make high-ENERGY compounds for use by the cell; SITE OF CELLULAR RESPIRATION

Type of Cell: found in eukaryotes

Analogy: it is like the power plant or coal-burning furnace of a factory

Chloroplast Physical Description: tubular organelle that

contains chlorophyll (a green pigment)

Function: use energy from SUNLIGHT to MAKE FOOD molecules through photosynthesis

Type of Cell: found in plant cells

Analogy: it is like the cafeteria OR solar energy panels of a factory

Centrioles Physical Description: bundles of microtubules

Function: part of the cytoskeleton that aids in cellular division

Type of Cell: found only in animal cells

Analogy: it is like the cranes used to move things in a factory

Cytoskeleton

Physical Description: a network of protein filaments in the cytoplasm; made of microtubules and microfilaments

Function: helps support the cell and maintain cell’s shape; moves organelles within the cell; aids in cell movement

Type of Cell: found in all cells

Analogy: it is like the support beams and cranes of a factory

Plant Cells vs. Animal Cells

Cell Wall Chloroplasts No Centrioles Lysosomes are

rare 1 Large Vacuole

No Cell Wall No Chloroplasts Centrioles Lysosomes are

common Several Small

VacuolesCells Alive Website

Job of Cells The main job of all cells is to

make proteins Different cells make different types Protein production:

Ribosome Endoplasmic Reticulum Golgi Apparatus Final Destination of the Protein (may

be outside of the cell)

POPQUIZ

Quick Quiz

1. Organelle that is the internal membrane system. It also has ribosomes and modifies proteins.

A. Golgi Apparatus

B. Lysosome

C. Rough ER

D. Smooth ER

Quick Quiz

2. Organelle that attaches carbohydrates and lipids to proteins; gives proteins the “address” of their final destination. Mail room of cell

A. Golgi Apparatus

B. Lysosome

C. Rough ER

D. Smooth ER

Quick Quiz

3. Which one of the following is not a part of the cell theory

A. All living things are composed of cells.B. All plant cells have a cell wallC. Cells are the basic units of structure and function in living thingsD. New cells are produced from existing cells.

Quick Quiz

4. Organelle that breaks down lipids, carbohydrates, and proteins into useable molecules; break down old or damaged organellesA. Cell membrane

B. Lysosome

C. Nucleus

D. Vacuole

Quick Quiz

5. Organelle that is usually near the center; contains the cell’s genetic material (DNA) a boss controls his/her employees

A. Cell membrane

B. Lysosome

C. Nucleus

D. Vacuole

Quick Quiz

Answers

1. C2. A3. B4. b5. C