Show Menu

Cell Structure and Function Cheat Sheet by

Biology, AP unit 2. Chapter 3 out of the 11 for AP biology

Cell theory

1. all livings things are made up of cells
Cells are small because they need to maintain a larger surface area to volume ratio.
2. cells are the smallest most basic unit of life
3. all cells come from pre-ex­isting cells


cell membrane- the cell membrane, provides protection for a cell. It also provides a fixed enviro­nment inside the cell, and that membrane has several different functions.
mitoch­ondria- mitoch­ondria produce the energy necessary for the cell's survival and functi­oning.
cytoplasm- The cytoplasm is respon­sible for holding the components of the cell and protects them from damage. It stores the molecules required for cellular processes and is also respon­sible for giving the cell its shape.
nucleus- The nucleus controls and regulates the activities of the cell (e.g., growth and metabo­lism) and carries the genes, structures that contain the hereditary inform­ation.
ribosomes- Ribosomes are minute particles consisting of RNA and associated proteins that function to synthesize proteins.
rough ER - In general, its function is to produce proteins. The rough endopl­asmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make those proteins.
smooth ER- The smooth endopl­asmic reticulum functions in many metabolic processes. It synthe­sizes lipids, phosph­olipids as in plasma membranes, and steroids.
golgi apparatus- Golgi apparatus, is a cell organelle that helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell.
vesicles - Vesicles can help transport materials that an organism needs to survive and recycle waste materials. They can also absorb and destroy toxic substances and pathogens to prevent cell damage and infection.
lysosomes- Lysosomes are involved with various cell processes. They break down excess or worn-out cell parts. They may be used to destroy invading viruses and bacteria.
vacuoles- Vacuoles are often used to store materials used for energy production such as starch, fat, or glycogen. Vacuoles and vesicles also transport materials within the cell and form around particles that enter by endocy­tosis.
chloro­plast- Chloro­plasts are plant cell organelles that convert light energy into relatively stable chemical energy via the photos­ynt­hetic process.
cell wall- The cell wall surrounds the plasma membrane of plant cells and provides tensile strength and protection against mechanical and osmotic stress. It also allows cells to develop turgor pressure, which is the pressure of the cell contents against the cell wall.
flagella- The primary function of a flagellum is that of locomo­tion, but it also often functions as a sensory organelle, being sensitive to chemicals and temper­atures outside the cell.

Cellular transport

Cellular Transport: the movement of ions and molecules across membranes. Cells must take up nutrients from the enviro­nment and export waste products.
The two major types of cellular transport are passive transport and active transport.

Passive Transport

simple diffusion- Simple diffusion is the movement of molecules through a cell membrane without using the channels formed by integral membrane protein. In the cell, examples of molecules that can use simple diffusion to travel in and out of the cell membrane are water, oxygen, carbon dioxide, ethanol and urea. They pass directly through the cell membrane without energy along the concen­tration gradient.
osmosis- Osmosis is the sponta­neous net movement of solvent molecules through a select­ively permeable membrane into a region of higher solute concen­tra­tion, in the direction that tends to equalize the solute concen­tra­tions on the two sides. An example of osmosis is feeling thirsty after having salty foods.
facili­tated diffusion- Facili­tated diffusion is the process of sponta­neous passive transport of molecules or ions across a biological membrane via specific transm­embrane integral proteins. The transport of glucose and amino acid from the bloods­tream into the cell is an example of facili­tated diffusion.

Active Transport

Primary active transport- Primary active transport, also called direct active transport, directly uses chemical energy to transport all species of solutes across a membrane against their concen­tration gradient.
Secondary active transport- Secondary active transport is a form of active transport across a biological membrane in which a transp­orter protein couples the movement of an ion down its electr­och­emical gradient to the uphill movement of another molecule or ion against a concen­tra­tio­n/e­lec­tro­che­mical gradient.
Endocy­tosis- Endocy­tosis is a cellular process in which substances are brought into the cell. The material to be intern­alized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material.
Exocyt­osis- Exocytosis is a form of active transport and bulk transport in which a cell transports molecules out of the cell. As an active transport mechanism, exocytosis requires the use of energy to transport material.

Water Potential

The formula for calcul­ating water potential is Ψ = ΨS + ΨP.
\Psi = water potential
\Psi_0 = reference correction
\Psi_pi = solute potential
\Psi_p = pressure component
\Psi_s = gravim­etric component
\Psi_v = potential due to humidity
\Psi_m = potential due to matrix effects
Water potential is the potential energy of water per unit volume relative to pure water in reference condit­ions. Water potential quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure and matrix effects such as capillary action.

Prokar­yotic vs. Eukaryotic

One chromosome is present, but not true chromosome plastids
Eukaryotic cells contain membra­ne-­bound organe­lles, such as the nucleus, while prokar­yotic cells do not.
Prokar­yotes are organisms that consist of a single prokar­yotic cell.
Eukaryotic cells are found in plants, animals, fungi, and protists.


No comments yet. Add yours below!

Add a Comment

Your Comment

Please enter your name.

    Please enter your email address

      Please enter your Comment.

          Related Cheat Sheets