62 terms

Biology Chapter 7 Vocabulary (Cell Structure and Function)

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Cells
The basic units of life
Cell Theory
A fundamental concept of biology which states that:

-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
A large membrane-enclosed structure that contains the cell's genetic material in the form of DNA
Eukaryotes
-Genetic material is contained in a nucleus, separate from the rest of the cell
-Highly specialized structures with internal membranes
-Larger and more complex
EX: Plants, animals, fungi, and protists
Eukaryotic cell structure
A cell divided into the two major parts of a nucleus and cytoplasm
Prokaryotes
-Genetic material is NOT contained in a nucleus
-Lack membrane-bound organelles
-Smaller and simpler
EX: Bacteria
Organelles
Specialized structure that performs important cellular functions within a eukaryotic cell
Cytoplasm
The portion of the cell outside the nucleus
Chromatin
Granular material that consists of DNA bound to protein/ during cell division, chromatin condenses into chromosomes
Chromosomes
Threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next
Nucleolus
Small, dense region within most nuclei in which the assembly of ribosomes begin
Ribosomes
Small particles of RNA and protein found throughout the cytoplasm (Assemble proteins by following coded instructions from the nucleus)
Endoplasmic reticulum
An internal membrane in eukaryotic cells where lipid components of the cell membrane where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell
Rough Er
Ribosomes on it's surface and is involved in protein synthesis
Smooth Er
Ribosomes NOT found on it's surface and contains enzymes that preform specific functions
Golgi apparatus
-Receives proteins produced in the rough ER
-Appears as a stack of closely apposed membranes
-Modifies, sorts, and packages proteins and other materials from the ER
-Proteins are used for storage inside and secretion outside the cell
-Proteins are then sent to their final destinations in/out of the cell
Lysosomes
-Small organelles filled with enzymes
-Break down lipids, carbs, and proteins into small molecules that can be used y the rest of the cell
-Also break down organelles that have outlived their usefulness
Vacuoles
Sac-like structures that store materials such as water, salts, proteins, and carbohydrates (give support and drain excess water)
Mitochondria
Organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use (enclosed by an outer and inner membrane)
Chloroplasts
-Exclusively in plants and other organisms
-Capture energy from sunlight and convert it into chemical energy though photosynthesis
-Surrounded by two membranes
-Contain the green pigment chlorophyll
Cytoskeleton
-Network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement
-It's made up of Microfilaments and Microtubules
Cell membrane
-A thin, flexible barrier that surrounds all cells
-Provides protection and support to the cell
Cell wall
-Strong supporting layer around the cell membrane in plants, algae, and some bacteria
-Lies outside the cell membrane
-Porous to allow H2O, CO2, and O2 to pass through
Diffusion
-Solute particles in a solution tend to move from an area which thy are highly concentrated to an area where they are less concentrated
-When the concentration of the solute is the same throughout a system, the system has reached equilibrium
-Depends upon random particle movements; does not require energy
Equilibrium
When the concentration of a solute is the same throughout a solution
Osmosis
The diffusion of water through a selectively permeable membrane
Isotonic
When the concentration of two solutions is the same (same strength)
EX: Body fluid
Hypertonic
When comparing two solutions, the solution with the greater concentration of solutes
EX: Salt water/ vinegar
Hypotonic
When comparing two solutions, the solution with the lesser concentration of solutes
EX: Pure water
Facilitated diffusion
-Movement of specific molecules across cell membranes through protein channels
-Does NOT require energy
Active transport
-Energy-requiring process that moves material across a cell membrane against a concentration difference
-Materials move against a concentration gradient
Phagocytosis
Cytoplasmic extensions surrounded and package a particle within food vacuoles within the cell
Pinocytosis
Tiny pockets form along the cell, fill with liquid and pinch off to form vacuoles within the cell
Exocytosis
-Membrane of the vacuole surrounding material in a cell fuses with the cell membrane
-Forces contents out of the cell
Cell specialization
The process in which cells develop in different ways to perform different tasks
EX: Animal cells
Tissue
Group of similar cells that perform a particular function
Organ
Group of tissues that work together to perform closely related functions
Organ system
Group of organs that work together to perform a specific function
Robert Hooke
First person to see cells
Anton van Leeuwenhoek
Observed tiny organisms in pond water
Theodor Schwann
Zoologist who observed that tissues of animals had cells
Matthias Schleiden
Botanist who observed that tissues of plants contained cells
Rudolph Virchow
Reported that every living thing is made of cells, predicted that cells come from other cells
Animalcule
A minute or microscopic animal, nearly or quite invisible to the naked eye
Transmission electron microscope
-Used to study cell structures and large protein molecules
-Specimens must be cut into ultra-thin slices
Scanning electron microscope
-Produce 3D images of cells
-Specimens do NOT need to be cut
Confocal light microscope
-Scan cells with a laser beam
-Makes 3D images of cells and their parts possible
Scanning probe microscope
-Observe single atoms
-Images produced by tracing surfaces of samples with a fine probe
Fluid mosaic model (Cell membrane)
Thin flexible barrier that regulates what enters/ leaves the cell (provides protection and support to the cell)
Nuclear pore
-A protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm. In eukaryotic cells, the nucleus is separated from the cytoplasm and surrounded by a nuclear envelope.
-GET RID OF WASTE
Microfilaments
-Threadlike structures made up of the protein actin
-Form extensive networks in some cells
-Produce a tough, flexible framework to support the cell
-Helps some cells move
Microtubules
-Hollow structures made of the proteins known as tubulins
-Maintain cell shape
-Important in cell division
-Build projections from the cell surface (Cilia, flagella, spindle fibers, centrioles) that enable cells to swim
Lipid bilayer
Double-layered sheet that gives the cell membrane a flexible barrier between it and it's surroundings
Proteins
Embedded in the lipid bilayer, some have crab molecules attached to them
Semi-permeable membrane
Allows some molecules to pass through, but not others
Passive transport
Does not require the cell to expend any energy and involves a substance diffusing down its concentration gradient across a membrane
Endocytosis
The taking in of matter by a living cell by invagination of its membrane to form a vacuole
Unicellular
An organism consisting of a single cell
Multicellular
An organism consisting of multiple cells
What structures do plant cells have that animal cells do not?
-Cell wall
-Vacuole
-Chloroplast
What are the four levels of organization in a multicellular organism are what? (In order from least to greatest)
L-Individual cells
-Tissues (group of similar cells with a particular function)
-Organs (group of tissues with a particular function)
G-Organ systems
What is the path of protein in a cell?
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