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Biology Chapter 7 Dictionary - Coggle Diagram
Biology Chapter 7 Dictionary
A cell
is the basic structural and functional unit of all living organisms.
A Vacuole:
is a sac used to store food, enzymes, and other materials needed by a cell. Some vacuoles store waste products.
Prokaryotic Cells
are defined as cells without a nucleus or other membrane-bound organelles.
Proteins
Receptor Proteins:
When found on the outer surface of the plasma membrane, proteins called receptors transmit signals to the inside of the cell.
Support Proteins:
Proteins at the inner surface anchor the plasma membrane to the cell’s internal support structure, giving the cell its shape
Transport Proteins:
move needed substances or waste materials through the plasma membrane and therefore contribute to the selective permeability of the plasma membrane.
Selective Permeability:
by which a membrane allows some sub- stances to pass through while keeping others out.
Recall that the process of maintaining balance in an organism’s internal environment is called
homeostasis
The nucleus
is a distinct central organelle that contains the cell’s genetic material in the form of DNA.
Phospholipid Bilayer:
in which two layers of phospholipids are arranged tail-to-tail,
Eukaryotic cells
contain a nucleus and other organelles that
are bound by membranes, also referred to as membrane-bound organelles.
Within the nucleus is the site of ribosome production called the
Nucleolus
Together, the phospholipids in the bilayer create a “sea” in which other molecules can float, like apples floating in a barrel of water. This “sea” concept is the basis for the
Fluid Mosaic Model
The Cell Theory
The cell theory is one of the fundamental ideas of modern biology and includes the following three principles:
All living organisms are composed of one or more cells.
Cells are the basic unit of structure and organization of all living organisms.
Cellsariseonlyfrompreviouslyexistingcells,withcellspassing copies of their genetic material on to their daughter cells.
The organelles that help manufacture proteins are called
Ribosomes
The Golgi apparatus
is a flattened stack of membranes that modifies, sorts, and packages proteins into sacs called
Vesicles.
The
Endoplasmic Reticulum
also called ER, is a membrane system of folded sacs and interconnected channels that serves as the site for protein and lipid synthesis.
Lysosomes:
are vesicles that contain substances that digest excess or worn-out organelles and food particles
Centrioles:
are organelles made of microtubules that function during cell division.
Both have a plasma membrane, but one cell contains many distinct internal structures called
organelles
—specialized structures that carry out specific cell functions.
Plasma Membrane:
is a special boundary that helps control what enters and leaves the cell.
The environment inside the plasma membrane is a semifluid material called
Cytoplasm
The cytoskeleton
is a supporting net- work of long, thin protein fibers that form a framework for the cell and pro- vide an anchor for the organelles inside the cells.
Cells also have energy generators called
Mitochondria
Chloroplasts:
which are organelles that capture light energy and convert it to chemical energy through a process called photosynthesis
The Cell Wall:
is a thick, rigid, mesh of fibers that surrounds the outside of the plasma membrane, protects the cell, and gives it support
Cilia:
are short, numerous projections that look like hairs. The motion of cilia is similar to the motion of oars in a rowboat.
Flagella
are longer and less numerous than cilia.
Diffusion:
which is the net movement of particles from an area where there are many particles of the substance to an area where there are fewer particles of the substance
The diffusion of water across a selectively permeable membrane is called
osmosis.
Cells in a hypotonic solution If a cell is in a solution that
has a lower concentration of solute, the cell is said to be in a
hypotonic solution.
When a cell is placed in a
hypertonic solution
, the concentration of the solute outside of the cell is higher than it is inside.
When a cell is in a solution that
has the same concentration of water and solute as its cytoplasm, the cell is said to be in an
isotonic solution.
This movement of substances across the plasma membrane against a concentration gradient requires energy; therefore, it is called
active transport
.
Another form of transport, called
facilitated diffusion
, uses transport proteins to move other ions and small molecules across the plasma membrane.
This condition, in which there is continuous movement but no overall change, is called
dynamic equilibrium.
Hessa Alkassim 12B
Endocytosis:
is the process by which a cell surrounds a substance in the outside environment, enclosing the substance in a portion of the plasma membrane.
Exocytosis:
is the secretion of materials at the plasma membrane.