A View of the Cell

Cell Structure & Function

Discovering the Cell

Robert Hooke– used a

microscope to study cork coined the term “cell”

Anton van Leeuwenhoek– first person to record looking at

water under a microscope

Chp. 7-1 Life is Cellular

I. Introduction to the Cell

A. Cell Theory

– All organisms are made upof one or more cells.

– Cells are the basic unit of structure & function in organisms.

– All cells come from preexisting cells.

B. Cells differ in size, shape, & organization.

B. Cells differ in size, shape, & organization.

– Cell Size Small cells function more efficiently than

large cells. Large cells cannot function efficiently in

the transport of materials & waste into and out of the cell.

B. Cells differ in size, shape, & organization.

– Cell Shape The shape of cell depends on its function.

– Most cells contain a variety of membrane bound ORGANELLES - cell parts that PERFORM SPECIFIC FUNCTIONS FOR THE CELL

C. Internal Organization

– A Large Organelle near the Center of the Cell is the NUCLEUS.  IT CONTAINS THE CELL'S GENETIC INFORMATION AND CONTROLS THE ACTIVITIES OF THE CELL.

– Whether a cell has or does not a NUCLEUS is important for classifying cells.

II. Prokaryotes Vs. Eukaryotes

EUKARYOTES “true” nucleus– ORGANISMS WHOSE CELL OR CELLS

CONTAIN A NUCLEUS AND OTHER MEMBRANE-BOUND ORGANELLES.

PROKARYOTES “before” the nucleus– ORGANISMS WHOSE CELLS NEVER

CONTAIN (OR LACK) A NUCLEUS AND OTHER MEMBRANE-BOUND ORGANELLES.

– Smaller (simple) than Eurkayotes– UNICELLULAR ORGANISMS such as bacteria

and blue green algae.

Note: The difference between Prokaryotes and Eukaryotes is such an important distinction that they are placed in separate Kingdoms.

•Notes 7-2 organelles•Grade Venn Diagram•Chapter 7 packet due FRIDAY!

•HW – Pre-lab due tomorrow!!

September 20

III. Parts of the Eukaryotic Cell

Structures in a cell are determined by the specific functions carried out by the cell.  Thus, there is N0 Typical Eukaryotic Cell.

A. Cell Boundaries

Animal cell Plant cell

CONTROL CENTER of the Cell NUCLEAR ENVELOPE

– Covered with many

small pores that allow

messages, like RNA,

to be sent from the

Nucleus

B. The Nucleus

B. The Nucleus

DNA– Hereditary information

NUCLEOLUS – MAKES (syntheisizes)

RIBOSOMES, WHICH IN TURN, BUILD PROTEINS

CHROMATIN – Consists of DNA bound

to protein

• EVERYTHING BETWEEN THE CELL

MEMBRANE AND THE NUCLEUS

• Is a jellylike mixture that consists

MOSTLY OF WATER

C. Cytoplasm / Cytosol

• Network of long protein strands give the

3D structure of the cell (SHAPE)

• Consists of TWO Types of structures:

- MICROFILAMENTS (threadlike)

- MICROTUBULES (hollow)

• HELPS THE CELL MOVE

and helps the organelles

with in the cell move!

D. Cytoskeleton

1. MITOCHONDRIA and CHLOROPLASTS

• Source of energy in plant and animal cells

• Only organelles that contain their own genetic

information in the form of DNA molecules

E. OrganellesEach organelle has a specific function that contributes to cell survival.

MITOCHONDRIA• "POWERHOUSE" OF THE

CELL• Converts chemical energy

stored in food into compounds that the cell can use- ATP is the molecule that most cells use as their main energy source- ATP production is called CELLULAR RESPIRATION

E. Organelles

CHLOROPLASTS

• Capture energy from sunlight and convert it into chemical energy in a process called

Photosynthesis

• Not found in animal cells

2. RIBOSOMES

• Are the site of PROTEIN SYNTHESIS

• Some float free in the cytoplasm; others

attach to the ROUGH ENDOPLASMIC

RETICULUM

E. Organelles

3. ENDOPLASMIC RETICULUM (ER)

• Can be ROUGH OR SMOOTH

• System of membranous tubules that connect

the Nuclear Envelope to the Cell Membrane

to transport materials

• Functions Primarily as an

transportation system

Ex. Transports protiens–

from rER to the Golgi

E. Organelles

4. GOLGI BODY

• Processing, Packaging, and Secretion

• System of membranes made of flattened sac like structures

Then the golgi sends the proteins out of the cell using the vesicles.

E. Organelles

5. LYSOSOMES

• Digestion of macromolecules

(lipids, carbohydrates, and proteins)

into molecules that can be used by the cell

• Involved in breaking down old cell parts

E. Organelles

6. CILIA AND FLAGELLA

• Extend from the surface of the cell

• Assist in movement

• CILIA ARE SHORT HAIRLIKE PROJECTIONS

• FLAGELLA ARE LONG WHIPLIKE

PROJECTIONS

E. Organelles

7. VACUOLES

• Membrane-bound spaces used for temporary storage of materials.

E. Organelles

VacuoleAnimalCell

PlantCell

A Tour of the Cell

September 23, 2010

PAP- Biology

Notes – Chapter 7-3 and 7-4

QUIZ??? HW- Pre-lab Semi permeable membrane

Turn in Onion and Cheek Cell LAB @ end of period– Check for: Drawing Name, Correct labels, color,

straight lines ect….

A. Cell Boundaries (more detail) – Chp. 7.3

Animal cell Plant cellCell / Plasma

Membrane –gate keeper,

allows materials in and out of

the cell

Cell Wall – provides

support & protection,

usually made of

tough fibers

Complex barrier separating the cell from it's external environment

Provides protection & support Is arranged in a double layer

called a Lipid Bilayer –

Made up of Phospholipids

(a phosphate group

& 2 fatty acids)

1. The Cell Membrane

1. The Cell Membrane

"Selectively Permeable" membrane that regulates

(like a gate) what passes into and out of the cell

Cell Membranes are FLUID Lipids and Proteins of the Cell Membrane are

always in motion

1. The Cell Membrane

Diffusion– Movement of particles from an area of high

concentration to an area of low concentration– Substances diffuse across membranes

without requiring the cell to use energy Osmosis

– Diffusion of water through a selectively permeable membrane

1. The Cell Membrane

Diffusion & Osmosis

Membrane Proteins– PROTEIN MOLECULES are EMBEDDED in

the Lipid Bilayer– HELP to MOVE larger Material INTO and

OUT of the Cell

1. The Cell Membrane

– often have carbohydrates attached to them to serve as I.D. badges that allow cells to recognize each other

1. The Cell Membrane

1. The Cell Membrane

Facilitated Diffusion / Passive Transport – down hill (easy)– Uses proteins to move molecules

through a cell membrane along the concentration gradient

– high low

1. The Cell Membrane

Active Transport – up hill (hard)– Uses proteins to move molecule against the

concentration gradient (high low)– Requires energy

1. The Cell Membrane

Exocytosis and Endocytosis

Exocytosis – process of a cell releasing materials Endocytosis – process of cell taking materials in

Exocytosis

Exocytosis and Endocytosis

Concentration – the mass of solute in a given volume of solution

Equilibrium – when the concentration of solute is the same throughout a solution

Phagocytosis – process in which extensions of cytoplasm surround & engulf large particles and take them into the cell (Exp. Amoeba)

Pinocytosis – process by which the cell takes in a liquid from the surrounding environment

Levels of Organizatio

nSubatomic particles →

Atoms → Molecules

Organic molecules →

Cells → Tissue →

Organs → Organ systems

→ Organism →

Population →

Community →

Ecosystem → Biosphere

Textbook p. 21

Diversity of Cellular Life

Cell Specialization – separate roles for each type of cell in multicellular organisms – Cells throughout an organism can develop in

different ways to perform different tasks

Chp. 7-4

Levels of Organization in Multicellular Organisms

Individual cells → Tissues → Organs → Organ systems

Muscle cell

Smooth muscle tissue

Stomach

Digestive system

Levels of Organization in Multicellular Organisms

Tissue – group of similar cells that perform a particular function

Organ – group of tissues that work together to perform closely related functions

Organ system – group of organs that work together to perform a specific function

Cell Structure (concept map)

Cells

prokaryotic eukaryotic

bacteria organelles

protists

fungi

plants

animals

can be

which are known as

which lack which

contain

which are

found in