Cell structure and function
Download
1 / 46

Cell Structure and Function - PowerPoint PPT Presentation


  • 102 Views
  • Uploaded on
  • Presentation posted in: General

Cell Structure and Function. Cell Discovery and Theory. The Cell. A cell is the basic unit of structure and function Humans have trillions and trillions of cells You can’t see cells with the naked eye. Cell Dudes. Robert Hooke- 1665

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Cell Structure and Function

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


Cell Structure and Function

Cell Discovery

and

Theory


The Cell

  • A cell is the basic unit of structure and function

    • Humans have trillions and trillions of cells

    • You can’t see cells with the naked eye


Cell Dudes

  • Robert Hooke- 1665

    • Looked at cork, saw little box-shaped structures and called it cellulae

  • Anton van Leeuwenhoek- late 1600s

    • Looked at pond water and milk and saw

      “beasties”


Cell Dudes

  • Matthias Schleiden- 1838-botanist

    • Studied plants and concluded that all plants are made of cells

  • Theodor Schwann- zoologist

    • Concluded that all animal tissues were made of cells

  • Rudolph Virchow- Suggested that cells come from cells


How do we know cells come from other cells?


Problem?

  • A compound light microscope has a 10X ocular lens and a 460X objective lens.

    • Where is the ocular lens? ____________________

    • Where is the objective lens? _________________

    • What is the total magnification ___________X


Prokaryotes

  • 2 Kingdoms

    • Eubackteria

    • Archeabacteria

  • No nucleus

  • DNA in a central nucleoid

    region

  • Contains ribosomes

  • First organisms on earth


Eukaryotic Cells

  • 4 Kingdoms

    • Protist (single celled)

    • Plants (cell wall/chloroplasts)

    • Animals (lack cell wall/lack chloroplasts)

    • Fungi (cell wall/lack chloroplasts)

  • Contain membrane bound organelles

    • Organelles are specialized structures that carry out functions


The Cell Membrane

  • The cell membrane is selectively permeable

    • Some things can pass but others can’t

  • Cell membranes are made from a phospholipidbilayer


Outside

of cell

Carbohydrate

chains

Proteins

Cell

membrane

Inside

of cell

(cytoplasm)

Protein

channel

Lipid bilayer

PhospholipidBilayer Structure

  • Each phospholipid has a polar head and two nonpolar tails

    • Polar head is attracted to water

    • Nonpolar tails are repelled by water


PhospholipidBilayer Function

  • The function is to let some things in and not others

    • Polar molecules do not easily pass

      • H2O is an exception because it is small

      • Allows membrane to separate environment inside from outside the cell

    • The plasma membrane is always in motion

      • Fluid mosaic model


Animal Cells/Plant Cells

  • Eukaryotic cell which makes up tissues in animals

  • Lack cell walls and chloroplasts, and have smaller vacuoles.

  • Appears to be circular because of the lack of a rigid cell wall.

  • Eukaryotic cell that makes up plants

  • Cell Wall

  • Chloroplast

  • Large Vacuoles


Animal Cell


Plant Cell


Cytoplasm

  • Semi-fluid material inside the plasma membrane

  • Consists of cytosol and the cellular organelles (all organelles except the cell nucleus)

  • Cytosol - fluid in which the cellular organelles are suspended


Cytoskeleton

  • Network of long, thin protein fibers provide an anchor for organelles

  • Microtubules-long hollow cylinders that assist in moving substances within the cell

  • Microfilaments-thin threads that give the cell shape and enable the cell to move

Cytoskeleton in

Red and Green


Nucleus

  • Contains genetic material (DNA)

  • Nuclear envelope

  • Nuclear pores allow substances in and out

  • Nucleolus in center

    • Very dense center


Produce proteins

Made of RNA and protein

Made in the nucleolus

Some float freely in the cytoplasm

Others attach to endoplasmic reticulum

Ribosomes


Endoplasmic Reticulum

  • Interconnected network of tubules

  • Rough ER

    • Where ribosomes attach and make proteins

    • Appear to create bumps and rough areas on the membrane

  • Smooth ER

    • No ribosomes

    • Produces complex carbohydrates and lipids


Golgi Apparatus

  • Modifies, sorts, and packs proteins in sacs called vesicles

  • Vesicles fuse with plasma membrane

  • They release proteins which move through membrane to get outside of the cell


Vacuoles

  • Act as temporary storage unit for materials in the cytoplasm

  • Store, transport, or digest food and waste

  • Plant cells have one large one

  • Animal cells have little ones


Lysosomes

  • Vesicles that contain digestive enzymes to digest excess or worn-out organelles and food particles

  • They also digest bacteria and viruses that enter the cell

  • They are built in the Golgi apparatus.


Centrioles

  • Microtubules

  • Found near nucleus

  • Animal Cells only

  • Aid in cell replication


Mitochondria

  • Powerhouse

  • Converts organic materials into energy

    • ATP

  • Outer and inner membranes with lots of folds

    • Provides large surface area to break sugar molecule bonds (produce energy)


Chloroplasts- Plant only

  • Capture light energy and convert it to chemical energy through photosynthesis


Cell Wall

  • Mesh of fibers that surrounds the plasma membrane

  • Protects and supports the cell

  • Made of carbohydrate, cellulose


Cilia and Flagella

  • Cilia- short projections that look like hairs

    • Move back and forth like oars on a rowboat

    • Move substances along surface of the cell

  • Flagella- longer projections that move in a whip-like motion

  • Both are composed of microtubules

  • Move cells through watery environment


Cell Transport

  • Diffusion -net movement of particles from high concentration to low concentration

    • Doesn’t require energy because the particle are in motion

  • Dynamic equilibrium- the overall concentration does not change, but molecules are still moving randomly


What affects the rate of diffusion?

  • What makes molecules move faster

    • High temperature

    • High Pressure

    • High concentration


Facilitated Diffusion

  • Some ions and molecules can’t diffuse across the cell membrane

  • Facilitated diffusion – uses transport proteins to help move some molecules across the plasma membrane


Osmosis

  • Osmosis – diffusion of water

  • Most cells undergo osmosis because they are surrounded by water


Hyper—Hypo– Iso tonic

  • These are comparing words

    • Hypertonic -more solute than

    • Hypotonic- less solute than

    • Isotonic- same solute as

  • What would happen if you

    • Put a red blood cell in a hypertonic solution

    • Put a red blood cell in a hypotonic solution

    • Put a red blood cell in an isotonic solution


Active Transport

  • Goes from low to high concentration

  • Requires Energy

    • ATP

  • Moves large substances


Endocytosis

  • Endocytosis- moving large substances into the cell


Exocytosis

  • Exocytosis- moving large substances out of the cell


ad
  • Login