Studied by 7 peopleActive transport
The movement of particles from an area of lower concentration to an area of higher concentration across the cell membrane using energy
Golgi apparatus
An organelle in cells that modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell
Homeostasis
Relatively constant internal physical and chemical conditions
Microtubules
Are like thin, hollow pipes made up of proteins known as tubulins
Lysosome
The cell organelle that breaks down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell
Endocytosis
The process of taking material into the cell through a pocket of the cell membrane that folds into the cell
Microscope
Gives you a larger view of something very small, such as a cell
Microfilaments
Threadlike structures made up of a protein called actin that supports the cell and helps some cells move
Eukaryotes
Cells that enclose their DNA in nuclei
Ribosomes
Cell organelles consisting of RNA and proteins found throughout the cytoplasm in a cell; are the site of protein synthesis
Nucleus
The _______ is a structure that contains the cell's genetic material in the form of DNA and controls many of the cell's activities
cellular junctions
In order to communicate, certain cells form connections, or ________, to neighboring cells some of which hold cells together firmly, and others that allow small molecules carrying chemical messages or signals to pass from one cell to the next.
stiff layer
All cells are surrounded by a barrier known as the cell membrane, and many cells also have a(n) ________ around the membrane known as a cell wall.
Single
________- celled organisms include both prokaryotes and eukaryotes.
Cytoskeleton
The network of protein filaments in a eukaryotic cell that gives the cell its shape and internal organization and is involved in movement
chloroplasts
Inside the ________ are large stacks of other membranes that hold the green pigment chlorophyll.
Endoplasmic reticulum
The internal membrane system found in eukaryotic cells and the place where lipid components of the cell membrane are assembled
Diffusion
The process by which molecules of a substance move from an area of higher concentration to an area of lower concentration
nuclear envelope
The ________ is dotted with thousands of holes that allow material to move into and out of the nucleus.
Exocytosis
Many cells release large amounts of material through a process known as _______
Osmosis
The diffusion of water through a selectively permeable membrane
Protein synthesis
________ occurs on ribosomes- a cell organelle consisting of RNA and protein found throughout the cytoplasm in a cell.
Small molecules
________ or ions move across a cell membrane through the work of protein pumps found in the membrane.
Prokaryotes
Cells that do not have nuclei and their DNA is not separated from the rest of the cell
higher concentration
When the solution outside of the cell has a(n) ________ than the inside solution, the outside solution is hypertonic.
Plants
________ and some other living things have chloroplasts- organelles found in cells of plants and some other organisms that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis.
Vacuoles
Large, membrane sacs that store materials like water, salts, proteins, and sugars
Light microscopes
Use glass lenses to focus light and magnify the object
Robert Hooke
In 1665, ________ used a microscope to look at thin slices of cork from plants that seemed to be made of many tiny, empty boxes; Hooke called these boxes "cells, "and they are the basic units of life.
Tissue
A group of similar cells that perform a particular function
lower concentration
When the solution outside of the cell has a(n) ________, it is hypotonic.
Scanning electron microscopes
In ________, a beam of electrons is scanned over the surface of an object to give a three-dimensional image of the object's surface
nuclear envelope
The nucleus is surrounded by a(n) ________ made up of two membranes.
chloroplasts
Both ________ and mitochondria have their own genetic information in the form of small DNA molecules.
Microtubules
Help the cell keep its shape and are also found in hairlike organelles called cilia and flagella
endoplasmic reticulum
Many ribosomes are free in the cytoplasm, while others are attached to the ________.
osmosis
In ________, as in all diffusion, molecules move from higher concentrations to lower concentrations- lower concentrations of water.
chloroplasts
Like ________, mitochondria are surrounded by two membranes- an outer membrane and an inner membrane.
Despite their differences, at some point in their lives, all cells have DNA
the molecule that carries genetic information; all cells are also surrounded by a thin, flexible barrier called a cell membrane
There are two main kinds of cells
one kind has a nucleus, and the other does not
Even though they are simpler than eukaryotes, prokaryotes do all the activities that living things must do to be called "alive
" they grow, reproduce, respond to the environment, and, in some cases, glide along surfaces or swim through liquids
Its easy to divide each eukaryotic cell into two major parts
the nucleus and the cytoplasm (the fluid portion of the cell outside the nucleus)
Many structures in plant and animal cells act like specialized organs and are known as organelles
specialized structures that perform important cellular functions within a eukaryotic cell
Protein synthesis occurs on ribosomes
a cell organelle consisting of RNA and protein found throughout the cytoplasm in a cell
Rough ER
Proteins are made on the rough ER; it is called "rough" because the ribosomes on its surface make it bumpy
Smooth ER
The smooth ER is called "smooth" because there are no ribosomes on its surface; in many cells, the smooth ER has groups of enzymes that make membrane lipids and get rid of toxins, such as drugs
Plants and some other living things have chloroplasts
organelles found in cells of plants and some other organisms that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis
Nearly all eukaryotic cells, including plant cells, have mitochondria
cell organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use
The special lipids in the cell membrane have two parts
a head and a tail
Sometimes there are differences in concentration of salts, sugars, proteins, and other dissolved molecules on one side of the cell membrane that produce a force known as osmotic pressure
the pressure that must be applied to prevent osmotic movement across a selectively permeable membrane
Cells
The basic units of life
Cell theory
States that all living things are made up of cells, that cells are the basic units of structure and function in living things, and that new cells come from existing cells
Electron microscopes
Produce even higher magnifications by using electrons instead of light
Transmission electron microscopes
Send beams of electrons through thin slices of cells and tissues
DNA
The molecule that carries genetic information
Cell membrane
A thin, flexible barrier that all cells are also surrounded by
Cytoplasm
The fluid portion of the cell outside the nucleus
Organelles
Specialized structures that perform important cellular functions within a eukaryotic cell
Nucleolus
The small, dense area in the nucleus is the _______, where ribosomes are first put together
Vesicles
Small membrane sacs that store and move materials between organelles as well as to and from the outside of the cell
Chloroplasts
Organelles found in cells of plants and some other organisms that capture the energy from sunlight and convert it into chemical energy
Mitochondria
Cell organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use
Cell wall
A stiff layer around the cell membrane whose main job is to support, shape, and protect the cell
Lipid bilayer
A double-layered sheet that makes membranes flexible and lets them form a strong barrier between the cell and its surroundings
Permeable
If a substance is able to cross a membrane, the membrane is said to be _______ to it
Selectively permeable
Most cell membranes are _______, which means that some substances can pass across them and others cannot
Passive transport
The movement of materials across the cell membrane without using cellular energy
Facilitated diffusion
The process of diffusion in which molecules pass across the membrane through cell membrane channels
Isotonic
When the solutions inside and outside of the cell are the same, the solutions are said to be _______
Hypertonic
When the solution outside of the cell has a higher concentration than the inside solution, the outside solution is _______
Hypotonic
When the solution outside of the cell has a lower concentration, it is _______
Osmotic pressure
The pressure that must be applied to prevent osmotic movement across a selectively permeable membrane
Organ
A group of tissues that work together to perform closely related functions
Organ system
A group of organs that work together to perform a specific function
Note
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