Cells Summary PDF

Cells summary By P’Pream Interplus+ Chapter 3 Cells 1. What is Cell? Most basic unit of organism or building block of an organism - building blocks and fundamental units of an organism. - Cell was discovered by an English scien...

Cells summary By P’Pream Interplus+ Chapter 3 Cells 1. What is Cell? Most basic unit of organism or building block of an organism - building blocks and fundamental units of an organism. - Cell was discovered by an English scientist Robert Hooke using cork. - The shape and size (Round, Oval, Long, Short, Tail) of the cells vary according to their functions and compositions. 2. Two types of cells (Prokaryote and Eukaryote) Prokaryotic cells Eukaryotic cells 1. No nucleus. The genetic material is 1. Have Nucleus. freely suspended. This region is called the 2. Size 10–100 μm in diameter “Nucleoid”. 3. Examples : plants, fungi, and animals. Cell membrane 2. Unicellular microorganisms. 4. Plasma membrane is responsible for 3. Diameter 0.1 - 0.5 μm monitoring the transport of nutrients 4. Prokaryotes reproduce by binary and electrolytes in and out of the cells. fission, a form of asexual reproduction. communication. It is also responsible for 5. Examples: archaea, bacteria, and cell to cell cyanobacteria. 5. Reproduce sexually as well as asexually  3. Summary of Microscope Types 1. Simple Microscope ( - Basic: Single lens magnifying instrument. - Low magnification: Typically used for examining small objects with the naked eye. - Examples: Magnifying glass, jeweler's loupe. 2. Compound Microscope - Multiple lenses for higher magnification. - Uses light to illuminate and magnify the specimen. - Components: Eyepiece, objective lens, stage, light source. - Commonly used: In biological research.,tissue, cells and small organisms. 3. Scanning Electron Microscope (SEM) - Uses a beam of electrons to scan the sample's surface. - 3D images - Don’t need thin section and stain - Can’t see internal structures and very expensive - Uses: surfaces of living and non-living specimens 4. Transmission Electron Microscope (TEM) - Transmits electrons through a thin specimen to form an image. - Provides detailed internal structure of the sample. - Can’t use living specimens, very thin specimens often need stains and are very expensive. - Uses: Cells organelles, microbes and virus Feature Simple Compound SEM TEM Image Refraction of Refraction of Electron beam Electron beam Formation light light scanning transmission Magnification Low Medium to high High Very high Sample Minimal Thin sections Coating with Ultra-thin Preparation conductive sections material Image Type 2D 2D 3D surface 2D internal structure Clean up checklist ❏ Remove slide ❏ Lower stage ❏ Switch to the lowest objective lens ❏ Turn off light ❏ Secure power cord and cover 4. Plant and Animal cell  Characteristic of a cell It provides structure and support to the body of an organism. Made of different individual organelles surrounded by a separate membrane. Nucleus (major organelle) holds genetic information necessary for reproduction and cell growth. A vacuole is a membrane-bound cell organelle. In animal cells, vacuoles are generally small and help sequester waste products. In plant cells, vacuoles help maintain water balance. Sometimes a single vacuole can take up most of the interior space of the plant cell. วน อ or Wal phospholipid - bilayer = Cell Wall Cell membrane / Plasma membrane %ข Only in plants, it is tough, flexible and Thin film which is a semi-permeable membrane sometimes rigid in its texture. composed of· lipids and proteins. It is mainly composed of cellulose, long Function: fibers of carbohydrates including 1. Protecting cell. hemicellulose, lignin 2. Providing support and maintaining the shape Function: of the cell. 1. Protecting cell 3. Regulating cell growth through the balance of 2. Regulates and controls the direction endocytosis and exocytosis. of cell growth. 4. Cell signaling and communication. 3. Providing the structural support and 5. It acts as a selectively permeable membrane maintaining the shape of the cell. by allowing the entry of only selected 4. Storing carbohydrates, especially in substances into the cell. seeds. 5.It allows entry of smaller molecules through it freely. ท่ ส่  Structure of a cell Protoplasm = Nucleus + Cytoplasm Nucleus is spherical in shape and covered by nucleus membrane. It contains DNA. Ribosomes are the site of protein synthesis. They may be found freely in the cytoplasm or may be found attached to the endoplasmic reticulum. Ribosomes are the complex organs that contain RNA (ribonucleic acids).These organelles are present in both eukaryotic and prokaryotic organisms. Golgi Apparatus :A flat, smooth layered, sac-like organelle which is located near the nucleus and involved in manufacturing, storing, packing and transporting the particles throughout the cell. Chloroplast: organelles that conduct photosynthesis Vacuole: a space in the cytoplasm,helps in maintaining shape and storing water, food, waste. Lysosomes digest unwanted materials in the cell. It also known as suicide bags of the cell. Lysosomes work as the waste disposing of structures of the cells. The key function of lysosomes is the removal of wastes and participation in digestion. Endoplasmic reticulum plays a significant role in the internal organization, by synthesizing selective molecules and processing, directing and sorting proteins to their appropriate locations. Roug - RER: having several ribosomes on its outer surface, - prominent in cells where protein synthesis happens and It synthesizes and secretes proteins in the liver, hormones and other substances in อ I protein the glands. - #th SER: has a tubular form and does not have ribosomes. SER are essential in the process of metabolism. SER transports the products of RER to other organelles, especially the Golgi apparatus. Energy Mitochondria: Power house of the cell, mitochondria generate the majority of our adenosine triphosphate (ATP), the energy currency of the cell. ○ Helping turn the energy we take from food into energy that the cell can use. ○ Signaling between cells and cell death, otherwise known as “Apoptosis”. ต่  Plant Cell VS Animal Cell Similarities: - Have cell membrane , nucleus, cytoplasm, ribosomes and mitochondria - Essentially, both plant and animal cells possess the basic organelles necessary for carrying out essential life processes. Plant Cell Animal Cell generally bigger generally smaller Fixed by cell wall Irregular and may vary during life Position of nucleus: May be to one Position of nucleus: usually at the side of the cells center Have cell wall and chloroplasts No cell wall, No chloroplasts Lack of lysosome and centrosomes small or no vacuoles Have large vacuole Food storage: Glycogen granules Food storage: Starch granules cover ก slip ↳slide  Types of Cell Cell Type Location Function Key Image Characteristics Nerve Cell Nervous Communication, Long axons, Thin (Neuron) system Transmitting fiber electrical signals Bone Cell Bone tissue Protection, Create a - Hard matrix, rigid frame for calcium and muscular movement, phosphorus Mineral storage - Bone is highly specialized connective tissue Red Blood Cell Blood Oxygen transport Biconcave shape, hemoglobin Reproductive Reproductive Reproduction Specialized for Cell organs fertilization (Sperm/Egg) Epithelial Cell Covering of Protection, Tightly packed, (Safety shields) organs, skin various shapes Palisade Cell Plant leaf, Photosynthesis Chloroplasts, (Leaf cells) right below Vertically - 0000 the elongated, a - epidermis different shape and cuticle from the spongy mesophyll cells Guard Cell Plant leaf - Gas exchange by Bean-shaped regulating the surround a opening & closing of stoma, a stoma. chloroplasts - They are the channels through which water is released from leaves to the environment Root Hair Cell Plant root Water absorption Long, thin from soil by osmosis projections, and transport to the Have a large Xylem. permanent vacuole Fat Cell Adipose Energy storage, Large lipid droplet (Lipocyte) tissue insulation Unicellular Consist of one cell Microorganisms Sea, lakes and rivers Carry out all life processes Multicellular % ู ↓ % # E Consist of many cells Carry out all life processes Each type of cell has a different structure and carries out only specific functions.  How does cell size affect the transport of materials? Nutrients, oxygen, and other materials move through the cell membrane. For a cell to successfully transport materials, the surface area of the cell must be large compared to its volume. The volume is the amount of space inside the cell. When a cell grows, both its surface area and its volume increase. However, the volume of the cell increases faster than its surface area. If a cell becomes too large, it would need large amounts of nutrients. It would produce large amounts of waste material. Its surface area would be too small to move enough nutrients into the cell and remove all of the waste materials from the cell How are cells organized in the body? The first(stem Cells) cells made can become any type of cell, such as a muscle cell, a nerve cell, or a blood cell, through the process of cell differentiation. Groups of similar cells that work together to carry out specific tasks are called tissues. Humans and most other animals have four main types of tissue. Muscle tissue helps in movement inside and outside. ○ Smooth muscle helps with the movement of waste and blood throughout the body ○ Skeletal muscle helps with the movement of bone ○ Cardiac muscle are striated muscles found in the heart Connective tissue provides structure and support. Often, it connects other types of tissues. Nervous tissue carries messages to and from the brain. Epithelial tissue lines the interior of organs and internal body cavities and forms the outer layer of skin. เ อเยื่อ อ ระบ ( Diffusion แพร Osmosis น มาก -> > High → Low concentration High → Low water concentration. Ex. Oxygen diffuses out from the lungs Net movement of water molecules across into blood vessels and CO2 diffuse out from a semipermeable membrane the blood vessels to the lungs Ex water moves into plant cells of roots Gas exchange takes place Kidneys water is reabsorbed by Osmosis Also called passive transport น้ำ นื้ น้  เ มข นส า สารลละลายเ ม ูง เ สารละลาย ข้ ท่ ข้ ข้