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Chapter 7 Cell Structure and Function

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Robert Hooke
-used an an early compound microscope to look at a cell
-called these chambers "cells"
Anton van Leeuwenhoek
-used a single- lens miocroscope to observe pond water and things
Matthias Schleiden
-concluded that all plants were made of cells
Theodor Schwann
stated that all animals were made of cells
Rudolf Virchow
stated that new cells could only be produced from already existing cells
Cell Theory
- All living things are composed of cells,
- Cells are the basic units of structure and function in living things.
-New cells are produced from existing cells.
Nucleus
-is a large memebrane- enclosed structure that contains the cell's genetic material in the form of DNA.
-makes proteins and other important molecules.
Prokaryotes
- do not contain a nuclei
- cells have genetic material that is not contained in a nucleus
-basic, no nucleus, no organelles, bacteria
- grow, reproduce, respond to the environment and some can even move by gliding along surfaces or swimming through liquids
Eukaryotic
- contain a nuclei
- cells contain a nucleus in which thier genetic material is seperated from the rest of the cell
-complex, nucleus, has organelles
-plants, animals, fungi, protists, and humans
- divided into two major parts: nucleus and cytoplasm
Organelles
specialized structure that performs important cellular functions within a eukaryotic cell.
Cytoplasm
- is the portion of the cell outside the nucleus .
Nuclear Envelope
-surround the nucleus
-has pores
-composed of lipoproteins (lipids/protein)
-selective permeable(lets certain things in and lets certain things out)
Chromatin
- granular material inside the nucleus.
-Composed of DNA and protein.
-Loose.
-Pass on traits and control the cell
Nucleolus(nucleoli)
- small, dense regions inside the nucleus
- assembly of ribosomes (make proteins)
-makes rRNA & tRNA
Nucleoplasm
-is liquid material inside the nucleus.
-Made of H2O,protein, and other chemicals
Ribosomes
-produced bythe nucleolus
-site of protein synthesis
-small particles of protein and RNA
-Attached to Endoplasmic Reticulum (rough)
-Free or attached
Endoplasmic Reticulum (E.R)
-there are 2 types of E.R.
-Found throughout the cytosol
-a system of membranes forming tubes and channels
-lipid compoonents for cell membranes are assembled, along with proteins
-Find them in cytoplasm
Smooth Endoplasmic Reticulum
- makes membrane materials
- smooth surface
- makes lipids/membrane material
Rough Endoplasmic Reticulum
- makes proteins
- has ribosomes
- attached ribosomes
Golgi Apparatus
-the Golgi Apparatus sorts, Chemically Alters, Modifies, and Packages important molecules
-accepts and releases incoming vesicles from the E.R.
-Materials are either stored in the cell or secreted outside the cell.
-stack of closely apposed membranes
Lysosomes
-cell's Digestive System
-"cleanup crew"of the cells
-breaks down macromolecules into useable parts
-breakdown outlived organelles
-comes from the Goligi Apparatus
Vacuoles
-serves water regulatuion, support, and storage
-stores H20 salts, proteins and carbs
-freshwater organisms have contractile vacuole
Mitochondrion
-converts chemical energy stored in food into energy easier for the cell
-called the powerhouse
-has outer and inner membrane
-ATP is created here
Chloroplasts
-convert sunlight into energy
-only in plant cells
-green in color
-surrounded by two membranes
Filaments/Cytoskelton
microfilament
-threadlick for cell movment
-smaller
Microtubules
-movement .
-hollow structures used to maintain cell shape and cell division(Centrioles)
-larger
Cilia/Flagella
1-threadlike and absorb/ move materials. helps with respiatory system
2-cell movement specifically
Centrioles
-help organize cell division
-found near nucleus
Cell Membrane
-cells are surrounded by a thin ,flexible barrier
-regulates what enters and leaves the cell and also provides protection and support
-have two thin layers of lipids(phospholid, bilayer
Carbohydrates- attached to proteins , cell identification
Proteins-help move materials across a membrane
Cell Wall
provide support and protection for the cell
-made of cellulose
Organisms and their cells need
water, gases, and ions
Plasma Membrane
all the cells are surrounded by a thin, flexible barrier
Selectively Permeable
the membranes regulation
Diffusion
-movement of molecules from an area of higher concentration to an area of lower concentration. Reaches an equilibrium
- does not require energy
Concentration
Concentration - mass of solute in a given volume of solution
Osmosis
-movement of water across a selectively permeable membrane
-cells must have a balance between intake and loss of water to survive.
-three types of soution: isotonic, hypertonic, hypotonic
Isotonic
-the concetration of solutes is the same inside and outside the cell
Hypertonic
Solution has a higher solute concentration than the cell(shrink)
Hypotonic
Solution has a lower solute concentration than the cell
swell in size
Facilitated Diffusion
-defined as a way for substances that cannot diffuse through a cell membrane on thier own move through protein channels instead.
-Only occurs from higher to lower concentration.
-does not require energy
Active Transport
-Moving aganist a concentration gradient (less to high)
-requires energy
-done either by pumps or protein channels.
Endocytosis and Exocytosis are used to move
larger molecules and even solid clumps across a membrane
Endocytosis
membrane folds inward to form a vacuole-like structure containing the matter needed.
Phagocytosis
extensions of cytoplasm surround a particle and package it within a food vacuole.
Pinocytosis
tiny packets form along the cell membrane, fill with liquids and pinch off to form vacoles within the cell
Exocytosis
releasing large amounts of material from the cell. Vesicle fuses with the cell membrane and forces contents out of the cell.
-ex Active Transport
Unicellular Organisms
- a single-celled oraganism
-some types of algae are single-celled
-include prokaryotes and eukaryotes
-some even live within the human body
Multicellular Organisms
-made up of many cells
Cell Specialization
-Cells through out an organism can develop in different ways to perform different tasks
-perform particular functions in the cell
-the human body contains scores of different cell types
-some cells are specialized to react to the environment
Four Levels of organization in Multicellular
cell
organs
tissues
organ system
Tissue
- is a group of similar cells that perform a particular function
Types of Tissues
muscle
nervous
epithelial-covers the entire body
nervous
connective
Organs
-group of tissues that work together to perform closely related functions
Organ System
group of organs that work together to perform a specific function.