Stnd: BI 4.d & 4c C-Notes: Cell Specialization & Sickle Cell Anemia (Cells, Tissue, Organs) 11/12/13 SWBAT recognize that cells in multi-cellular organisms differ in structure and function. Objective:

All organisms are composed of cells. Why is Cell Differentiation an important part of the development of a multicellular organism? This process is needed because one kind of cell cannot perform all the activities required for life. All organisms are composed of cells. Unicellular organisms consist of only 1 cell that performs all required function (job) to maintain life. Ex: Bacteria, Amoeba Multicellular organisms are composed of more than 1 cell because they are more complex and cells are specialized/differentiated to perform certain functions. The body needs to supply food and nutrients, transport materials, remove wastes and fight infection. Ex: Plants and animals

What are Specialized Cells? (Cell Specialization) Cells that differ in structure (size, shape) and function (the job they perform in the organism). Ex: bone cell, muscle cells, nerve cells, skin cells, stem cells, blood cells, etc. This is due to different patterns of gene expression rather than to differences of the genes themselves Advanced organisms (multi-cellular) have more specialized cells. An adult human is composed of approximately 100 trillion cells and has over 200 different types of specialized cells.

Examples of Cell Specialization Neuron (nerve cell) - send and receive signals/info from one part of the body to another (Coordinates body actions.) - very long and thin Ex: Brain will send a signal through nerve cells to control a muscle and create movement

Examples of Cell Specialization Red Blood Cells - Picks up Oxygen from the lungs and carries it to body cells throughout the body. - flattened round smooth disks so that they can easily flow through blood vessels

Examples of Cell Specialization Epithelial Cell cells that line the openings in the body and also cover flat surfaces (top layer). Ex: skin, pancreas, liver, lung and sinuses

Examples of Cell Specialization Muscle cells (3 types) I. Cardiac Muscle cells Found ONLY in your heart II. Smooth Muscle cells Found in the digestive tract and in the walls of blood vessels III. Skeletal Muscle cells found attached to your bones and helps you move. It also helps protect your inner organs.

Examples of Cell Specialization Bone Cell which are found within the bone tissue, are responsible for the make-up of the skeleton A collection of bone cells Will make bone tissue

Examples of Cell Specialization 4. Stem Cell These are NON-SPECIALIZED cells in humans that can develop (differentiate) into many different cell types. The daughter cells have the same DNA, but different genes may be turned on or off.

Stem Cell Research

Examples of Cell Specialization 5. Xylem and Phloem Cell (Root Cells) To absorb and transport materials (water/nutrients) throughout plants from the soil.

What is the Level of Organization of an Organism? Cell Organization: Cells: basic unit of structure and function of all living things. Ex: white blood cell, muscle cell Tissue: A group of similar cells performing the same function. Example: muscle tissue, blood tissue Organ: A group of specialized tissues performing one main function. Ex: stomach, kidney Organ System: A group of organs that carry on one of the major body functions. Ex: digestive system, nervous system Organism: An organism is made up of organ systems that perform its life functions. Ex: plants and animals

Levels of Organization Cells in higher organisms (sponges and up) are specialized to carry out specific functions such as reproduction, digestion, support, etc. In higher organisms (flatworms and up) cells of the same specialization congregate into tissues. A tissue then is a collection of cells that all perform the same specialized functions. As you can now easily guess – tissues organize, often in layers to make organs and organs in term make up organ systems which collectively make up organisms. Specialized cell make up the lining of your gut. These along with muscle cells and connective tissue cells organize into a tube, your esophagus. The esophagus is one organ in the digestive organ system that includes the stomach, small and large intestines, liver and pancreas.

Tissues in the Arm

Cell Specialization External Cues Stem Cells Internal Gene Regulation Cell Specialization is really all about which proteins are turned on when and for how long. Muscle cells need lots of the proteins actin and myosin that are involved in contraction. Liver cells need lots of digestive enzymes, Cells that line the lungs need enzymes for making mucus – a glycoprotein. Cell Specialization

What is Sickle Cell Anemia? It is a disorder/ disease caused by a single mutation (missense point mutation) in the DNA code for the protein “hemoglobin” in red blood cell that gives the production of red blood cells a sickle shape. In Sickle cell anemia , the DNA code contains a substitution of an adenine to a thymine, which causes the amino acid to change Valine Acid for Glutamic Acid (one amino acid change). Normal RBC’s contain hemoglobin that is 100% full of oxygen. Sickle Cell hemoglobin contains only about 70% oxygen and the shape can cause blockages in the blood vessels, preventing the RBC’s from reaching body cells with the oxygen they are carrying. This decrease in the ability to deliver oxygen is a reason why sickle cell anemia is a serious health threat.

Normal and Sickled Red Blood Cells in Blood Vessels Figure B shows abnormal, sickled red blood cells clumping and blocking the blood flow in a blood vessel. The inset image shows a cross-section of a sickled red blood cell with abnormal strands of hemoglobin. Figure A shows normal red blood cells flowing freely in a blood vessel. The inset image shows a cross-section of a normal red blood cell with normal hemoglobin. Source from http://www.nhlbi.nih.gov/health/dci/Diseases/Sca/SCA_WhatIs.html

…and how does it affect them? Blood Cells They die Blood Flow Not so good Body Parts/Organs Yeah, they’re affected Immune System As open as Detroit’s offensive line Normal blood cell – 120 days Sickle Cell – 16 days Red bone marrow cant keep up

Which one has sickle cells?