Chapter 3 sec 2 cell features
Sponsored Links
This presentation is the property of its rightful owner.
1 / 41

Chapter 3 Sec. 2: Cell Features PowerPoint PPT Presentation

  • Uploaded on
  • Presentation posted in: General

Chapter 3 Sec. 2: Cell Features. Cell Theory. All living organisms are made of one or more cells. Cells are the basic unit for both structure and function . Cells come from preexisting cells.

Download Presentation

Chapter 3 Sec. 2: Cell Features

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

Chapter 3 sec 2 cell features

Chapter 3 Sec. 2:Cell Features

Cell theory

Cell Theory

  • All living organisms are made of one or more cells.

  • Cells are the basic unit for both structure and function.

  • Cells come from preexisting cells.

    - not by spontaneous generation (mice from rags, worms from horse hairs) we believe in biogenesis

Robert hooke

Robert Hooke

  • Englishman

  • Looked at cork

  • Saw cubicals

  • 1st person to see cells – but they were dead cells.

Scientists involved in cell theory

Scientists involved in cell theory

  • Schleiden – All plants are made of cells

  • Schwann – All animals are made of cells

  • Virchow – All cells come from other cells

Differences in cells

Differences in Cells

  • Size –

    • biggest cell is ostrich egg

    • smallest is bacteria .002 mm

    • most are from 5 to 20 µm in diameter

Differences in cells1

Differences in Cells

  • The size of the cell is limited by the surface area to volume ratio.

    Surface area= amount of cell membrane available

    Volume= amount of material inside the cell

Surface area to volume ratio calculation activity

Surface Area to Volume Ratio Calculation Activity

  • Using 1 cm cubes, build a 2 cm x 2 cm x 2 cm block to symbolize a small cell.

  • Calculate the surface area by using the formula: (l x w x number of sides)

  • Calculate the volume by using the formula: (l x w x h)

  • Calculate the ratio by dividing the surface area by the volume.

  • Repeat using a 3 x 3 x 3 cell.

  • Repeat using a 4 x 4 x 4 cell.

What happens when the surface area to volume ratio gets too small

What happens when the surface area to volume ratio gets too small?

Cell division occurs!

Cells can be different by

Cells can be different by…

  • Internal organization (does it have a nucleus or not????)

Cell internal organization

Cell Internal Organization…

Prokaryotes: Organisms without a nucleus or any membrane bound organelles (ex. Bacteria & simple algae)

Eukaryotes: Have nuclei & membrane bound organelles

(ex. Humans, fish, trees, sponges)

Prokaryote characteristics

Prokaryote Characteristics:

  • First life forms on Earth (3.5 billion years ago)

  • May or may not need oxygen

  • Cytoplasm holds everything – enzymes, ribosomes, DNA, etc.

  • Have a cell wall surrounding cell membrane

  • Many have flagella for movement



  • All have a nucleus containing DNA

  • Have organelles outside the nucleus – internal compartments with specific functions to perform

  • Most organisms ARE eukaryotes!

Common features of cells

Common Features of Cells…

  • Cell Membrane

  • Cytoplasm

  • Cytoskeleton

  • Ribosomes

  • DNA

Common features of cells1

Common Features of Cells…

  • Cell Membrane

    - gatekeeper of the cell

    - is selectively permeable

    (allows only certain substances to pass in or out)

Parts of a cell

Parts of a cell…

  • Structure of the Cell Membrane

    - made of lipids and proteins (mostly lipids)

    - two layers thick

    (phospholipid bilayer)

Chapter 3 sec 2 cell features

  • Model of the cell membrane is called the Fluid Mosaic Model

The cytoskeleton

The Cytoskeleton:

  • Is the internal framework or support

  • Is composed of a protein fiber network

  • 3 different kinds of cytoskeleton fibers:

    • Microfilaments (fibers made of protein actin)

    • Microtubules (hollow – made of protein tubulin)

    • Intermediate fibers (thick protein ropes)

Section 3 cell organelles

Section 3:Cell Organelles

Cell parts the nucleus

Cell Parts-The Nucleus…

  • Is the Control Centerfor the cell

  • Contains DNA and RNA

  • Is filled with nucleoplasm and chromatin (dark grainy material that changes into chromosomes during cell division)

Cell parts the nucleus1

Cell Parts-The Nucleus…

  • Nucleus is contained by a nuclear membrane made of 2 layers

  • Nuclear membrane has pores to allow materials to leave nucleus

Cell parts the nucleus2

Cell Parts-The Nucleus…

  • Has a nucleolus (small dark oval inside)

  • Nucleolus produces ribosomes

Parts of the cell

Parts of the cell…

  • Endoplasmic Reticulum (E.R.)

    The cell’s subway system

Endoplasmic reticulum

Endoplasmic Reticulum

  • Materials (especially proteins) are transported from one area to another.

  • 2 kinds of ER – smooth and rough

  • Smooth has no ribosomes attached.

  • Rough has lots of ribosomes attached.

  • Vesicles form when ends of ER pinch off as a membrane sac

Parts of the cell1

Parts of the cell…

  • Ribosomes

  • Are produced in the nucleolus

  • They produceproteins

  • Are located on the surface of endoplasmic reticulum and also free floating in the cytoplasm.

  • Are made of ribosomal-RNA

Parts of the cell2

Parts of the cell…

  • Golgi Apparatus


Golgi apparatus

Golgi Apparatus

  • Proteins packaged in vesicles move to Golgi apparatus - also called Golgi bodies or golgi complex

  • GA looks like stacks of flattened pancakes

  • GA areproteinprocessing centers – refined, processed & packaged.



  • Are small spherical structures that contain digestive enzymes that allow cells to recycle its materials.

  • Lysosomes act as the “recycling center” for the cell.

Protein packaging distribution

Protein Packaging & Distribution

  • Made at ribosomes on ER & packaged into vesicles

  • Travel from ER to Golgi Apparatus

  • Get processed & repackaged at GA

  • Move from GA to cell membrane for export

Mitochondria mighty mitochondria

Mitochondria: (mighty mitochondria)

  • produce ATP energy by breaking down glucose

  • have double membranes

  • have in and out folds called Cristae

  • Have ring of DNA



Parts of the cell3

Parts of the cell…

  • Which cells have the most mitochondria?

    High energy requiring

    cells like muscles!

Parts of the cell4

Parts of the cell…

  • Cilia & Flagella

  • Used for movement of the cell

  • Cilia are short and numerous

  • Flagella are usually 1-2 in number and very long like a whip

  • Made of sets of microtubules

Structures of plant cells

Structures of Plant Cells

Plant cells

Plant Cells

  • All plant cells have a Cell Wall

    - on the outside of cell membrane

    - provides cell support & strength

    - made of cellulose - a carbohydrate

Plant cells1

Plant Cells…

  • Central Vacuole

    - are storage spots in cytoplasm

    - very large

    - may store water, enzymes, waste products, or even toxins

Plant cells2

Plant Cells…

  • Contain Plastids

    - are membrane bound structures

    - have their own type of DNA

    3 kinds:

    • Chloroplasts

    • Leucoplasts

    • Chromoplasts

Plant cells3

Plant Cells…

  • Have Chloroplasts:

    - green

    - membrane bound structures

    - store chlorophyll (green pigment needed for photosynthesis) so…

    - chloroplasts are the sites of photosynthesis.

Plant cells4

Plant Cells…

  • Leucoplasts:

    - are white structures inside cells

    - are storage areas for produced food.

    - Ex: Potato grains stained in lab.

    - may be other starchy materials like corn, wheat

Plant cells5

Plant Cells…

  • Chromoplasts –

    are the colored pigments seen in petals of flowers or in leaves in fall.

  • Login