Honors Biology Cell Structure & Function/Material Exchange Learning Targets

Cell Structure & Membrane Transport

Differentiate between prokaryotic and eukaryotic cells. * Define and give an example of each type of cell. 1pts

Prokaryotic cells don’t have a nucleus, have circular DNA that floats in the cytoplasm, and are unicellular (ex: bacteria). Eukaryotic cells have a nucleus, have DNA in the nucleus, and can be multicellular but don’t have to be (ex: plant & animal cells).

Create a Venn diagram to show how prokaryotic and eukaryotic cells are similar and different. Your diagram should have AT LEAST 6 differences and 4 similarities. 2.5pts

Differentiate between animal and plant cells.

Create a Venn diagram to show how animal and plant cells are similar and different. Your diagram should have AT LEAST 4 differences and 8 similarities. 3pts

Explain how major systems and processes work together in animals and plants.

Explain each of the levels of organization from organelles through organisms, describing how they are connected to one another. 1pt

The levels of organization begin with molecules and end with organisms. Molecules make up cells, the same cells together determine the function of tissues, different tissues make up organs, which form organ systems with different organs, and different organ systems make up organisms like us.

Choose 4 organelles within a plant or animal cell. Describe where they’re located in the cell, their function, and how they interact with one another. 1pt

The cell membrane is present in both plant and animal cells. It’s located outside the cell, and its function is to protect the cell and control the entry/exit of substances. The cytoplasm is present in both plant and animal cells. It’s located everywhere inside the cell; its function is to help the other organelles move around. The ribosome(s) is located in both plant and animal cells. It’s located in the cytoplasm and on the rough endoplasmic reticulum; the function is to make proteins. The golgi apparatus is found in both plant and animal cells as well. Its location is in the cytoplasm throughout the cell. Its function is to store proteins and prepare them for export.

Be sure you know all of the organelles on your study chart - even though you don’t have to re-write the chart for this learning target, you still need to know it! Ok

Propose how moving an organism to a new environment may influence its ability to survive and predict the possible impact of this transfer.

Differentiate between hypertonic, hypotonic, and isotonic. 3pts

A hypertonic solution is where there is more solute within the solution than in the sac membrane, so water is drawn out of the sac and the cell shrinks. A hypotonic solution is where there is less solute within the solution than in the sac membrane, so water flows into the cell, causing expansion and swelling. An isotonic solution is where the solution/concentration of solutes is the same both inside and outside the sac; there is a balance/equilibrium, so the cell stays the same/is unaffected.

Explain the impact of hypotonic, hypertonic, and isotonic solutions on plant and animal cells. Use vocab terms to describe the changes in each type of cell. 2pts

The impact of hypotonic solutions on plant and animal cells is that it causes them to swell because water moves from the hypotonic solution into the cell (to try to create a balance in concentration). The impact of hypertonic solutions on plant and animal cells is that they will shrink because water moves out of the cell into the solution through osmosis. The impact of isotonic solutions on plant and animal cells is that they will stay the same. Water will not flow in or out of the cell. There will be the same amount of water concentration on both sides of the cell membrane.

Describe what would happen if you moved a saltwater plant to freshwater (or the other way around). 0.5 pt

If you moved a saltwater plant to freshwater, or the other way around, the plant would likely die if it cannot adapt to its new environment and conditions. If a freshwater plant were to be thrown in saltwater, it would wilt and die because water would keep moving out of the cell, cutting the plant off (hypertonic environment). If a saltwater plant were to be thrown in freshwater it would swell and maybe burst because the plant would be introduced to a hypotonic environment, so water would keep moving into the cell/plant.

Explain the role of cell membranes as highly sensitive barriers.

Describe the structure of the plasma membrane and explain how the structure relates to its function. 2 pts

The structure of the plasma membrane is a fluid, and it is a phospholipid bilayer. There are embedded proteins within the membrane, including transport proteins and glycoproteins. Transport proteins allow passage of molecules through the membrane. Glycoproteins (and glycolipids) are markers that identify the cell to other cells, and receive chemical signals from other cells. The structure relates to its function because the semi-permeable membrane allows certain molecules in while preventing others from doing so. The nonpolarity of phospholipid tails of the membrane prevent charged particles like ions from going in but allow the passage of fat-soluble molecules.

Differentiate between passive and active transport. Give examples of molecules transported via both methods. 2pts

Passive transport is when materials move across the cell membrane and down the concentration gradient without using cellular energy. Active transport is when molecules move across the cell membrane using cellular energy (in the form of ATP) and can move against the concentration gradient. Examples of passive transport are diffusion, where molecules move from high to low concentration, osmosis, the diffusion of water through a selectively permeable membrane (high to low concentration of water), and facilitated diffusion, where transport proteins form a tunnel to allow molecules in. They move along the direction of the concentration gradient, so energy is not required. Examples of active transport are carrier proteins/pumps, where energy is used to pump substance up the concentration gradient (low to high concentration) and vesicles, which move large molecules via endocytosis (into the cell) and exocytosis (out of the cell).

Explain how size, polarity, and charge each impact the way materials are exchanged across the cell membrane. 2pts

Size impacts the way materials are exchanged across the cell membrane because smaller molecules can be difficult to diffuse across the cell membrane, and increased surface area of the cell may speed up diffusion. The cell membrane selects particles that have to be the right size, charge, and solubility to pass through. Polarity impacts the way materials move because polar molecules cannot pass through the membrane, while nonpolar molecules can pass through easily because of the nonpolar phospholipid tails of the lipid bilayer. Charge impacts the exchange of materials because charged particles like ions cannot pass through, but fat-soluble molecules can.

Extra Notes:

Bacteria = unicellular living organisms
Biofilm = bacteria colony w/different jobs but no communication
Advantages of volvox & algae = larger organisms cannot eat it anymore
Organelles, cells, tissues, organs, organ systems, organisms
Turgor pressure - hypotonic
Cytolysis - cell bursts from too much water