Cell structure 2013

Plant and Animal Cells

http://www.microscopy-uk.net/vidplanet/video/show/o1GQyciJaTA/online

Cells are the Starting Point

• All living organisms on Earth are divided in pieces called cells.

• There are smaller parts in cells that include proteins and organelles.

• Cells work together to make tissues, organs and organ systems.

• Cells are small compartments that hold all of the biological equipment necessary to keep an organism alive and successful on Earth.

Cells are the Starting Point

• A main purpose of a cell is to organize. Cells hold a variety of pieces and each cell has a different set of functions.

• It is easier for an organism to grow and survive when cells are present. If you were only made of one cell, you would only be able to grow to a certain size. You don't find single cells that are as large as a cow. Also, if you were only one cell you couldn't have a nervous system, no muscles for movement, and using the internet would be out of the question. The trillions of cells in your body make your life possible.

Cell Membrane

• When you think about a membrane, imagine it is like a big plastic bag with some tiny holes.

• That bag holds all of the cell pieces and fluids inside the cell and keeps any nasty things outside the cell.

• The holes are there to let some things move in and out of the cell.

Cell Membrane

• Outer membrane of cell

• Semi-permeable membrane that controls movement of materials in and out of the cell.

• Contains proteins

Cytoskeleton

• Supports cell and provides shape

• Helps move materials in and out of cells

• Composed of microtubules

Cytoplasm• Cytoplasm is the fluid that fills a cell. • The cell organelles are suspended in the cytoplasm. • The cytoplasm has many different molecules

dissolved in solution. You'll find enzymes, fatty acids, sugars, and amino acids that are used to keep the cell working.

Cytoplasm

• The cytoplasm in a cell does more than just suspend the organelles. It uses its dissolved enzymes to break down materials.

• The products can then be used by the organelles of the cell.

Cytoplasm

• Cytoplasm is the fluid that fills a cell.• Contains the cell materials

• A thick jelly like substance in which organelles float.

Centrioles

• Paired cylindrical organelles near nucleus

• Involved in cellular division

• Are at right angles to each other

• Composed of nine tubes, each with three tubules

Nucleus

• The cell nucleus acts like the brain of the cell.

• It helps control eating, movement, and reproduction.

• If it happens in a cell, chances are the nucleus knows about it.

• The nucleus is not always in the center of the cell. It will be a big dark spot somewhere in the middle of all of the cytoplasm. You probably won't find it near the edge of a cell because that might be a dangerous place for the nucleus to be.

Nucleus

• It is the largest

organelle.

• One or more per

cell.

• The cell nucleus acts like the brain of the cell - controls cell activities.

• It helps control eating, movement, and reproduction.

Chromosomes

• Found in the nucleus of each cell, the DNA molecule is packaged into thread-like structures.

• Holds the code that control the cell. Contains genetic information

• Composed of DNA

• Set number per species (i.e. 23 pairs for human)

Nuclear membrane

• Surrounds nucleus

• Composed of two layers

• Controls movement of materials in and out of the nucleus.

Nucleolus

• Spherical shape

• Visible when cell is not dividing

• Contains RNA for protein manufacture

Nucleolus

• an organelle within the nucleus - it is where ribosomal RNA is produced.

Mitochondrion• Mitochondria are known as the powerhouses of the

cell.

• They are organelles that act like a digestive system that takes in nutrients, breaks them down, and creates energy for the cell.

• The process of creating cell energy is known as cellular respiration.

Mitochondrion• The process of creating cell energy is known as

cellular respiration.

• Most of the chemical reactions involved in cellular respiration happen in the mitochondria. A mitochondrion is shaped perfectly to maximize its efforts.

• Mitochondria are very small organelles.

There are cells with several thousand mitochondria. The number depends on

the cell’s function.

• Located in the cytoplasm

• Rod-shaped bodies that release energy for cell use.

• they are the sites of cellular respiration which generates fuel for the cell's activities

• are also involved in cell division

releases energy from food

(Energy Plant)

Controls level of water and other materials in cell

Golgi Bodies• The Golgi bodies or Golgi complex is

found in most cells. • It is a packaging organelle.• The Golgi complex gathers simple molecules and

combines them to make molecules that are more complex.

• It then takes those big molecules, packages them, and either stores them for later use or sends them out of the cell.

Golgi Bodies

• It is also the organelle that builds lysosomes (cell digestion machines).

• Golgi complexes in the plant may also create complex sugars .

• The Golgi complex is a series of membranes shaped like pancakes.

Golgi Bodies

• Packages and move protein to the outside of the cell.

• Molecules are packaged for delivery to other cell components or for removal from the cell.

• Stores and release chemicals for cell use.

EndoplasmicReticulum (ER)

• The endoplasmic reticulum (ER) is responsible for the production of the protein and lipid components of most of the cell's organelles.

• The ER is additionally responsible for moving proteins and other carbohydrates to the Golgi apparatus, to the plasma membrane, to the lysosomes, or wherever else needed.

• It creates a network of membranes found through the whole cell.

EndoplasmicReticulum

(ER)• The ER may also look different from cell to

cell, depending on the cell's function.

• Rough ER looks like sheets of bumpy membranes while smooth ER looks more like tubes.

• Smooth ER acts as a storage organelle.

• Rough ER are very important in the synthesis and packaging of proteins.

• Tube network in cytoplasm where cell substances are made.

• Goes through cytoplasm into cell membrane

• Stores, separates, and serves as cell's transport system

• Smooth type: lacks ribosomes• Rough type (pictured): ribosomes embedded in surface• Breaks down lipids, and packages proteins for release from

the cell.

Ribosomes • Each cell contains thousands

• Miniature 'protein factories’

• Composes 25% of cell's mass

• Stationary type: embedded in rough endoplasmic reticulum

• Mobile type: injects proteins directly into cytoplasm

Ribosomes

• The smallest structures in the cell.

• Proteins are made in these.

• Lysosomes hold enzymes that were created by the cell.

• The purpose of the lysosome is to digest things.

• They might be used to digest food or break down the cell when it dies.

Lysosomes

• The lysosomes float in the cytoplasm until they are needed.

• Since lysosomes are little digestion machines, they go to work when the cell absorbs or eats some food.

• Once the material is inside the cell, the lysosomes attach and release their enzymes. The enzymes break down complex molecules that can include complex sugars and proteins.

Lysosomes

Lysosome• Digestive 'plant' for proteins, lipids, and carbohydrates It digests food particles, wastes, cell parts and foreign invaders.

• Moves undigested material to cell membrane for removal

• Varies in shape depending on process being carried out

• Cell breaks down if lysosome explodes

• “garbage man”

Vacuoles

• Membrane-bound sacs for storage, digestion, and waste removal

• Stores water and dissolved materials in the cell.

• Vacuoles are found in

plant and animal cells -

they are LARGER in plants!

Plant cells

Certain structures are found only in plant cells.

Cell Wall• Plant cells are easier to identify because they have

a protective structure called a cell wall made of cellulose.

• Plants and bacteria have a cell wall; animals do not.

• The tough wall gives added stability and protection to the plant cell.

Cell Wall

• Surrounds the plant cell; gives shape and provides support for the plant

• Controls turgidity (turgor pressure)

• Not found in animals, animals have bones that provide support

Chloroplast• Chloroplasts are the food producers of

plant cells. This is where photosynthesis occurs.

• They are only found in plant cells and some protists. A protist is any organism that is not a plant, animal or fungus, like algae.

• Animal cells do not have

chloroplasts.

Chloroplast

• Every green plant you see is

working to convert the energy

of the sun into sugars. This

process is called

photosynthesis.

• They create sugars, and the byproduct of that process is the oxygen that we breathe. That process happens in the chloroplast.

Chloroplasts

• Found in plant cells

• Controls green chlorophyll to captures sunlight to make food for the cell. (photosynthesis)

• Animal cells do not have chloroplasts.

Organelles: (1) nucleolus (2) nucleus (3) ribosome (4) vesicle (5) rough endoplasmic reticulum (ER) (6) Golgi apparatus (7) Cytoskeleton (8) smooth ER (9) mitochondria (10) vacuole (11) cytoplasm (12) lysosome (13) centrioles

Bibliography

http://www.cellsalive.com/cells/cell_model.htm

http://www.biology4kids.com/files/cell_main.html

http://en.wikipedia.org/wiki/Cell_nucleus

http://www.sparknotes.com/biology/cellstructure/celldifferences/section1.html

Videos

Cell Organelles And Their Function (BOTH 3D AND MICROSCOPIC VIEWS )http://www.microscopy-uk.net/vidplanet/video/show/LP7xAr2FDFU/online

Cell Structure and Function - Advanced Biotechnology Podcast 1.2 http://youtu.be/o1GQyciJaTA

A Tour of the Cell