* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download CELL STRUCTURE AND FUNCTION
Survey
Document related concepts
Cell membrane wikipedia , lookup
Signal transduction wikipedia , lookup
Tissue engineering wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cell growth wikipedia , lookup
Cytokinesis wikipedia , lookup
Cell nucleus wikipedia , lookup
Cell culture wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell encapsulation wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Transcript
CHARACTERISTICS OF LIFE 1. composed of cells – either uni/multi 2. reproduce – sexual and/or asexual 3. contain DNA in cells 4. grow and develop 5. use material/energy in metabolic reactions 6. respond to environment 7. maintain an internal balance - homeostasis 8. change over time – evolve as a population ORGANIZATION OF LIFE Cells are the basic unit of life. Groups of cells that perform a similar function are tissue. At least two tissues combine to form an organ. Organs that carry out similar functions are organized into systems. CELL THEORY TIMELINE Before the 17th century, no one knew cells existed. Most cells are too small to be seen with the unaided eye. 1600’s – Microscopes were invented. Robert Hooke, an English scientist, made an improved microscope and viewed thin slices of cork viewing plant cell walls. Hooke named what he saw “cells”. Anton Von Leeuwenhoek, a Dutchman, developed lenses with a stronger magnification to view microscopic organisms. 1800’s – Cell theory was formed. Matthias Schleiden (German botanist) & Theodore Schwann (German zoologist) stated that all plants and animals were made of cells. Rudolf Virchow (German physician) stated that cells only arise from pre-existing cells. Virchow’s idea contradicted the idea of spontaneous generation (idea that nonliving things could give rise to organisms). Principles of the Cell Theory 1. All living things are made of one or more cells. 2. Cells are the basic unit of structure & function in organisms. 3. Cells come only from the reproduction of existing cells. TYPES OF CELLS PROKARYOTES Lack nucleus Lack organelles Only unicellular EUKARYOTES Have nucleus Have membrane bound organelles Uni-/Multicellular Only Example bacteria Examples animal, plant, fungi, protist Cells differ in size, shape and function. ALL cells have these components – BOTH prokaryotic and eukaryotic cells: Endosymbiosis theory: All organelles seem to share many properties with bacteria. Lynn Margulis proposed endosymbiosis hypothesis: that organelles derived from ancient colonization of large bacteria (became the eukaryotic cell) by smaller bacteria (became the mitochondria, chloroplast, etc.) Symbiosis = "living together". In other words ---- eukaryotic cells evolved when prokaryote cells engulfed or absorbed other cells! CELL STRUCTURE AND FUNCTION Organelles are specialized structures INSIDE the cell that have their own functions. Although the cytoplasm and ribosome are not considered organelles, they are still structures found in the cell. Organelles function together to help the cell carry out all of life’s activities. Remember: ONLY EUKARYOTIC CELLS HAVE ORGANELLES!!!! STRUCTURE Cell or Plasma Membrane FUNCTIONS Double membrane barrier consisting of phospholipids and proteins -- separates the intracellular fluid within the cell and the extracellular fluid outside the cell. Controls the movement of materials into and out of cell to maintain homeostasis Cell Wall Thick, inflexible outer layer surrounding the cell membrane that provides support and protection Found in all cells BUT animal cells Cytoplasm Semi-fluid matrix (cytosol) containing organelles Provides support and protection for organelles Chromosomes (Chromatin) Contain the DNA found in the nucleus (of eukaryotic cells) and found in the nucleoid region (of prokaryotic cells) Prokayotes have a one, circular chromosome. Eukaryotes have linear chromosomes. Nucleus Contains the genetic material (DNA) that controls all cellular processes Genetic blueprint for cellular proteins – dictates type and amount of proteins synthesized STRUCTURE Nuclear Membrane (nuclear envelope) Nucleolus Ribosomes FUNCTIONS Double membrane barrier – outer layer is continuous with rough ER and inner lining maintains shape of nucleus Pores allow substances to pass – regulates transport of molecules into and out of the nucleus Dense cluster of RNA and proteins that will be assembled into subunits of ribosomes – RIBOSOMES are produced! Synthesizes proteins – PROTEINS are produced! Free ribosomes synthesize soluble proteins that function in the cytosol or other organelles. Endoplasmic Reticulum (ER) Ribosomes on the Rough ER synthesize proteins to be exported from the cell. Membrane system of channels and flatten sacs that is continuous with the nuclear membrane and extends through cytoplasm – transports materials Rough ER – has ribosomes on surface; manufactures secretory proteins that will be wrapped in transport vesicles for outside transport Golgi Apparatus Smooth ER – no ribosomes on surface; contains enzymes for lipid metabolism Flattened sacs that contain enzymes for modification and packaging of proteins and lipids from the ER Packages proteins and lipids inside transport vesicles and sends them to their destination STRUCTURE Vacuole FUNCTIONS Vesicles that store water, amino acids, sugars, metabolic and toxic waste Plant cells have a large vacuole Lysosomes Vesicle containing digestive enzymes that digest ingested pathogens (bacteria or viruses) and nonfunctional organelles Peroxisomes RARELY found in plant cells Vesicles containing enzymes (oxidase and catalase) that detoxify harmful or toxic substances Chloroplast Site of photosynthesis - transforming sunlight energy directly into food Contains green pigment called chlorophyll Has own DNA and can self-replicate Mitochondria NOT found in animal or fungi cells Site of aerobic cellular respiration - Uses energy from food to make ATP (adenosine triphosphate) that the cell can use to grow, develop and move Has own DNA and can self-replicate Cytoskeleton Centrioles Very active cells have more mitochondria Network of protein filaments - microtubules and microfilaments Help give the cell shape, movement of organelles inside cell and provide support/strength Microtubules grow out of centrosome (central area of cell) and form centrioles Produce spindle fibers for separating chromosomes during nuclear division STRUCTURE Cilia FUNCTIONS Short, more numerous hair like structures that assist in cell movement or propelling foreign substances around the cell Flagella Long whip like tail used for cell movement