Cell Structure and Function What makes up cells? What do cell do?

Levels of Organization Organism Organ System Organ Tissue Cell

Cell Structure and Function Notes Discovery of the Cell: Mid 1600’s scientists began using microscopes to observe living things Robert Hooke used microscope to observe thin slice of cork—dead plant material Cork seemed to be made of box-like chambers—Hooke called cells Anton van Leeuwenhoek discovered living cells in pond water

Cell Theory: All living things composed of cells Cells are the basic unit of structure and function in living things New cells are produced from existing cells

Cell and its Environment: Organisms made of one cell—unicellular organisms Ex: bacteria Organisms made of many cells—multicellular organisms Ex: plants, animals

Each cell must be in “balance” with its environment, exchange food, waste, H2O, CO2, O2 etc. Process by which organisms maintain a relatively stable internal environment—homeostasis

Cell Parts and Functions Find out what all the organelles in a cell do and compare them to other items using analogies.

Cell Parts / Organelles Organelle is a fancy name for specialized parts of a cell. It means “little organs”. Plant and animal cells have many organelles, most of which they have in common.

Animal and Plant Cell

Organelles in Common The following are organelles that both plants and animals can have: Cell membrane Nucleus Nuclear membrane Endoplasmic Reticulum Ribosomes Golgi Bodies Vacuoles Mitochondria Chromatin Cytoplasm

Organelles Vary by Cell Plants usually also have cell walls and chloroplasts. Animals may also have cilia, flagella, and lysosomes.

Cell Membrane All cells have a cell membrane. The cell membrane protects the contents of the cell and regulates passage of materials into and out of the cell. The cell membrane is selectively permeable. This means that small molecules can slip through easily and that larger molecules are controlled as they pass in and out.

Cell membrane—determines what goes in and out of the cell

Selectively Permeable

A Cell Membrane is like… …your skin because they both protect internal parts and keep the whole together

Nucleus The nucleus has two major functions: 1- it keeps all the genetic material DNA; 2- it controls all the functions in the cell including growth, metabolism, protein synthesis, and reproduction (cell division). Only the cells of advanced organisms, known as eukaryotes, have a nucleus. Simpler one-celled organisms (prokaryotes), like the bacteria and cyanobacteria, don't have a nucleus. In these organisms, all of the cell's information is scattered throughout the cytoplasm.

Nucleus—control center of the cell Double membrane that surrounds the nucleus—nuclear membrane Hereditary information inside the nucleus—chromatin (DNA)

Cell Nucleus: Organisms that do NOT have a distinct nucleus—prokaryotic (PRO rhymes with NO) Ex: bacteria Organisms with cells that have true nucleus and organelles—eukaryotic (EU rhymes with TRUE) Ex: plants, animals, fungi

because it controls your body like the nucleus controls the cell. A Nucleus is like… … your brain because it controls your body like the nucleus controls the cell.

Nuclear Membrane The nuclear membrane is a double layer that holds the nuclear material DNA inside and regulates the passage of materials into and out of the nucleus. More than 20,000 ribosomes can be made by the nucleus in a minute and they need to be sent out into the cytoplasm through nuclear pores. The ER is connected to the nuclear membrane.

A Nuclear Membrane is like… … your skull because it protects your brain like the nuclear membrane protects the nucleus.

Chromatin and Chromosomes Chromatin is made up of chromosomes, which hold the genetic material: DNA!!!

Chromatin is like… …your brain cells because they are the genetic make up of your brain just like the DNA is the genetic make up of the cell.

Nucleolus The nucleolus is inside the nucleus and it is where the ribosomes are made.

Nucleolus is like… …your ??? because...

Endoplasmic Reticulum The endoplasmic reticulum manufactures, processes, and transports a wide variety of biochemical compounds for use inside and outside of the cell. It also acts like a pipe between the nucleus and the cytoplasm. There are two types of ER, rough ER (with ribosomes) and smooth ER (without ribosomes)

Rough Endoplasmic Reticulum (rough ER)— makes and transports proteins within the cell Called rough ER because of the ribosomes found on its surface

Smooth Endoplasmic Reticulum (smooth ER)—makes and transport lipids and other materials within the cell Called smooth ER because no ribosomes found on its surface

The Endoplasmic Reticulum is like… …your spinal cord because it is a pathway from the brain to the body which carries messages just like the ER carries messages from the nucleus to the cytoplasm.

Ribosomes Ribosomes are the protein makers of the cell. Proteins are necessary for all functions. They carry the messages that tell everything what to do and build. Brain cells and pancreas cell have the most ribosomes because they are constantly making proteins.

Ribosomes—make proteins

The Ribosomes are like… …individual cells because they are responsible for building up your body just like ribosomes build up proteins.

Golgi Bodies The Golgi Bodies are often considered the distribution and shipping department for the cell's chemical products. The Golgi Bodies modify proteins and lipids (fats) that have been built in the endoplasmic reticulum and prepare them for export outside of the cell or for transport to other locations in the cell.

Golgi apparatus—processes and packages proteins and other substances produced in the ER

The Golgi Bodies are like… …your digestive system because it transports materials outside the body like the golgi bodies transport things outside the cell.

Vacuoles Vacuoles provide structural support, storage space, waste disposal, and also help in protection and growth. Plant cell vacuoles are larger than animal cell vacuoles, and help to maintain the cell’s shape and structure.

Vacuoles—sac-like structures for storage Plant cells usually contain a large vacuole that fills most of the cell—pressure from this large vacuole helps plants support themselves

The Vacuoles are like… …your fat cells because they store excess material and they provide the body with shape just like the vacuoles do for the cell.

Mitochondria Mitochondria are the “powerhouse” of the cell. They convert oxygen and nutrients into adenosine triphosphate (ATP). The process mitochondria use to make energy is called respiration.

Mitochondria—energy source of the cell (powerhouse)

The Mitochondria are like… …your intestines because they breakdown food to get energy out of it just like the mitochondria do to get ATP.

Cytoplasm The cytoplasm is a jelly-like fluid that surrounds and cushions the organelles in the cell. The cytoplasm also helps the cell maintain its shape.

Cytoplasm—gel-like medium that holds the organelles in position

Cytoskeleton—network of protein filaments (scaffolding) within the cytoplasm that helps cell maintain its shape

The Cytoplasm is like… …your skeletal system because it provides a structure and support for all internal organs just like cytoplasm provides a cushion and support for the cell.

Lysosomes The main job of lysosomes is to digest materials no longer needed by the cell. The process of recycling the cell's organic material is known as autophagy. Lysosomes break down cellular waste products, fats, carbohydrates, proteins, and other macromolecules into simple compounds, which are then transferred back into the cytoplasm as new cell-building materials. Lysosomes are often made from the membrane of the golgi bodies.

Found in animal cells only: Lysosomes—cleans up the cell and digests unwanted materials

The Lysosomes are like… …the stomach because it uses acid to breakdown materials just like the lysosomes breakdown materials in the cell.

Cilia / Flagella Cilia and flagella are present in most microorganisms and animals, but not in higher order plants. The function of these parts is to allow for movement either of the cell itself or of something past the cell.

Cilia The respiratory tract in humans is lined with cilia that keep inhaled dust, smog, and potentially harmful microorganisms from entering the lungs. Among other tasks, cilia also generate water currents to carry food and oxygen past the gills of clams and transport food through the digestive systems of snails.

Flagella Flagella are found primarily on gametes, but create the water currents necessary for respiration and circulation in sponges and coelenterates as well.

Specialized Parts for movement: Cilia (like little hairs) Flagella (like a tail)

Pseudopodia Other forms of movements are seen with pseudopodia “false feet” or lamellipodia and filopodia – both projections of the cytoskeleton used for movement.

A white blood cell using pseudopods to engulf a yeast cell. Lamellipoda used to move this cell across a surface.

The Cilia and Flagella are like… … your arms and legs because they allow for movement of your body just like the cilia and flagella allow for movement of the cell.

Cell Wall The only plants have a cell wall which does many jobs: It protects the cell contents. It gives structure and rigidity to the plant. It provides a porous medium for the circulation and distribution of water, minerals, and other nutrients. And it houses specialized molecules that regulate growth and protect the plant from disease.

Found in plant cells only: Cell wall—provides support and protection for cell Composed mainly of cellulose (plant starch)—fiber for our diet

The Cell Wall is like… …the clothing you wear because it surrounds and protects your skin from the outside just like the cell wall surrounds and protects the cell membrane.

Chloroplast The chloroplast is present only in plants and some bacteria. The chloroplast has a very important function: it conducts photosynthesis. This means it traps sunlight and uses it to help make food.

Found in plant cells only: Chloroplast—makes glucose using the energy from the sun (photosynthesis)

The Chloroplast is like… …your mouth because it traps food to bring into your body to be made into useable energy just like the chloroplast traps sunlight to bring into the cell to be made into useable energy.

I think a ___ cell is like the human body

Specialized Cells: Different cells in your body do different jobs. The structure (how it’s built) of cells matches the function (what it does).

Plant Examples: Leaf cell—contains many chloroplasts to maximize photosynthesis Root cell (potato)—contains many vacuoles to maximize water and starch storage

Animal Examples: 1. Epithelial cells—have villi to increase nutrient absorption; found in the intestines chloroplast

2. Muscle cells—contain many mitochondria to produce more energy for movement

3. Nerve cells—have fibers called dendrites that allow nerve cells to communicate with each other

Your Turn!!! Now you get to make your own analogy. First you will need to choose a plant cell or an animal cell. Next you will need to list all the parts of the cell you chose. After that you should pick something to compare your cell to, like a car or a factory. Make an ANALOGY for each part of the cell to each part of the item you chose. USE COMPLETE SENTENCES TO EXPLAIN YOUR ANALOGY! For example: A nucleus is like your brain because your brain controls your body just like the nucleus controls the cell. Fourth you will make a rough sketch of your drawing and show Miss Habdas your written analogies to get checked off. Finally you will make a beautiful poster of your “imitation cell” and include all written analogies.

1st –Plant Cell or Animal Cell ???

2nd- List All Cell Parts cell membrane nucleus nuclear membrane Etc….

3rd- Compare Cell to ??? Make Analogies!!! A plant cell is like a car!!! The cell wall is like… The chloroplasts are like… An animal cell is like a house!!! The lysosome is like… The cilia are like…

4th- Make a Sketch & Show Miss Habdas

5th- Make a Beautiful Cell Analogy Poster!!!  See all class examples.

YOU ARE DONE!! The end 