Cells and Cell Systems

Cells and Cell Systems Video: Tour of the Cell

Review Cell Theory Two main ideas? 1) All Living things are composed of one or more cells. 2) All cells come from pre-existing cells

Review What are the 6 Characteristics of Living Things? Living things are: Compose of cells Reproduce, grow, and repair Require energy Respond to the environment Have a life span Produce waste

A quick review What is this? What are cells? Cells are the smallest units of life Most cells are very, very small, so tiny that they can only be seen with the aid of a microscope. Your body is composed of billions of cells! Within your body, cells have different functions. We have blood cells, skin cells, brain cells...the list goes on. Despite their differences, cells in living organisms for the most part have similar structures and functions. Scanning electron micrograph of human red blood cells

Anatomy of the Animal Cell 9 2 1 3 8 5 7 4 6

1) Cell Membrane Serves as a boundary between the cell and the outside environment Holds contents of the cell in place act as a gatekeeper, controlling the movement of materials into and out of the cell All consist of double layer of fat molecules The cell membrane is the thin nearly invisible structure that surrounds the cytoplasm of the cell. In the image at the left you can see that it is a continuous membrane that completely surrounds the cell. It also connects the endoplasmic reticulum, and the nuclear membrane. In the image below we have colored the membrane to highlight its composition. The yellow represents the phospholipids. The purple represents the membrane proteins structure BACK

2) Cytoplasm Contains everything between the cell membrane and the nucleus: organelles consists of primarily of water Site of chemical activities ie. dissolved gasses and nutrients Allow transportation between structures Store waste until depose BACK

3) Endoplasmic Reticulum (ER) Spreading throughout the cytoplasm Protein producing organelles A series of folded membranes giving it a very large surface area Provide surface area for cell reactions Site of lipid (fat) production Rough ER Has ribosomes Spreading throughout the cytoplasm It is a folded system of membranes that loop back and forth giving it a very large surface area. This membrane provides a surface area for cell reactions. It is also the Site of lipid production. Smooth ER Structure where fats (lipids) are made BACK

4) Ribosomes manufacture proteins for the cell Location: rER, cytoplasm BACK

5) Golgi Apparatus Looks like a stack of flattened pancakes Store protein (produced by rER) and puts them into packages called vesicles Release to the outside The golgi body is responsible for packaging proteins for the cell. Once the proteins are produced by the rough E.R. they pass into the sack like cisternae that are the main part of the golgi body. These proteins are then squeezed off into the little blebs which drift off into the cytoplasm. BACK

6) Lysosome produced by the golgi body Called suicide sacks Contain special proteins that used to breakdown large molecules (digestive enzymes) Patrol and clean cytoplasm Destroying harmful substances and bacteria that enter the cells Lysosomes are called suicide sacks. They are produced by the golgi body. They consist of a single membrane surrounding powerful digestive enzymes. BACK

7) Mitochodria Energy Production (power plant of the cell) Rod-shaped organelles Provide energy for cells Through process: cellular respiration sugar molecules + oxygen molecules carbon dioxide + water where cellular respiration takes place (the breakdown of sugars to produce energy for the cell, a process that uses oxygen and produces carbon dioxide and water) BACK

8) Nucleus Control center containing hereditary material (DNA) Direct all cell’s activities Surrounded by a membrane Cells with a nuclear membrane: Eukaryotic cells Those without a nuclear membrane: prokaryotic cells Ex. One-celled organism; bacteria BACK

9)Chromosomes Found inside the nucleus Contain DNA or genetic material Holds “construction plan” for all parts of the cell Duplicated and passed on to other cells

How do cells move? hair like extentions off of the cell membrane

Plant Cells Generally plant cells contain the same features as animal cells such as; Cell membrane Cytoplasm Nucleus sER and rER Have some special structures that are not found in animal cells cell membrane which serves as a boundary between the cell and the outside environment cytoplasm containing organelles nucleus containing hereditary material (DNA) mitochondrion (plural, mitochondria), where cellular respiration takes place (the breakdown of sugars to produce energy for the cell, a process that uses oxygen and produces carbon dioxide and water) smooth endoplasmic reticulum where lipids are made rough endoplasmic reticulum where proteins are made with the help of ribosomes

What structure do plant cells have different from animal cells? Vacuole Cell wall Chloroplast

Cell Wall Outside the cell membrane which provides additional strength Protects and supports the plant cell Have small openings (pores) that allow some molecules to pass through: Gases, water, some minerals Cell walls are the rigid structure found surrounding plant cells. They provide support for the plant BACK

Vacuole Water and nutrients storage (just as in animal cells) often with dissolved pigments, waste materials, or other substances Much larger in plants Store waste that is produced or absorbed by the plant Contractile vacoules These organelles are critical in enabling protozoa to combat the effects of osmosis. Protozoa must constantly excrete the water that enters through their membranes BACK

Chloroplast Double membrane, made up of stacked discs (thyakoids) and fluid (stroma) Energy source Food factory of the plant cells Contain chlorophyll (green chemical molecules) plant cells trap the energy of light and use it to manufacture food proteins for the cell Site of Photosynthesis Animal cells cannot do this What is chloroplast similar to in an animal cell? uses light energy to convert six carbon dioxide molecules into one organic six-carbon sugar Allow plants to make own food, using light from the sun, conbon dioxide and water (site of photosynthesis)

Homework: SSA practice In your textbook Pg. 13 #2-6 On your own, brainstorm about chromosome Come up with some visual examples that demonstrate what it does. May help to use action words in its definition as in what it is and what it does to decide what visuals you might use

Example: Cytoplasm Function: stores wastes Visual: a garbage; can store waste Remember: your visual doesn’t have to look like the that part of the cell, just the function

Extras Centrioles are found only in animal cells. They function in cell division. Notice the 9 sets of 3 arrangement of the protein fibers. References: The virtual cell page: Personal.tmlp.com

Animal Cells Under light microscope Under electron microscope http://www.umanitoba.ca/faculties/science/biological_sciences/lab3/biolab3_2.html

Plant Cells Under light microscope Under electron microscope