AP Bio unit 2 study guide

Describe the structural features of a cell that allow organisms to capture store and use energy.

-Chloroplasts are organelles found in the broccoli's cells, along with those of other plants and algae. They capture light energy and store it as fuel molecules in the plant's tissues. -Mitochondria are found inside of your cells, along with the cells of plants. The folding of the inner membrane increases the surface area, which allows for more ATP to be synthesized.

Describe the membrane-bound structures of the eukaryotic cell.

-Mitochondria are oval-shaped, double membrane organelles that have their own ribosomes and DNA. These organelles are often called the "energy factories" (ATP) -Golgi apparatus is where the sorting, tagging, packaging, and distribution of lipids and proteins takes place. -Peroxisomes are small, round organelles enclosed by single membranes; they carry out oxidation reactions that break down fatty acids and amino acids. -Vesicles and vacuoles are membrane-bound sacs that function in storage and transport. Other than the fact that vacuoles are somewhat larger than vesicles, there is a very subtle distinction between them: the membranes of vesicles can fuse with either the plasma membrane or other membrane systems within the cell. -Nucleus, DNA

Explain how osmoregulatory mechanisms contribute to the health and survival of organisms.

-Osmoregulation is the process of maintenance of salt and water balance ENE-2.I.1 Growth and homeostasis are maintained by the constant movement of molecules across membranes. ENE-2.I.2 Osmoregulation maintains water balance and allows organisms to control their internal solute composition/water potential.

Describe the mechanisms that organisms use to maintain solute and water balance.

-Solutes or water move across a semi-permeable membrane, causing solutions on either side of it to equalize in concentration. -Passive transport is the net movement of molecules from high concentration to low concentration without the direct input of metabolic energy. -Active transport requires the direct input of energy to move molecules from regions of low concentration to regions of high concentration.

Describe the role of the cell wall in maintaining cell structure and function.

A major role of the cell wall is to form a framework for the cell to prevent over expansion. Cellulose fibers, structural proteins, and other polysaccharides help to maintain the shape and form of the cell. Additional functions of the cell wall include: Support: The cell wall provides mechanical strength and support. Regulate diffusion: The cell wall is porous allowing some substances, including proteins, to pass into the cell while keeping other substances out.​ Storage: The cell wall stores carbohydrates for use in plant growth, especially in seeds. Withstand turgor pressure: Turgor pressure is the force exerted against the cell wall as the contents of the cell push the plasma membrane against the cell wall.

Describe the processes that allow ions and other molecules to move across membranes.

A variety of processes allow for movement of ions and other molecules across membranes, including passive and active transport, endocytosis, and exocytosis. -ions move though ion channels down the concentration gradient

Describe the Fluid Mosaic Model of cell membranes.

Cell membranes consist of a structural framework of phospholipid molecules that is embedded with proteins, steroids (such as cholesterol in eukaryotes), glycoproteins, and glycolipids that can flow around the surface of the cell within the membrane.

Explain how the structure of a molecule affects its ability to pass through the plasma membrane.

ENE-2.G.1 -Membrane proteins are required for facilitated diffusion of charged and large polar molecules through a membrane - a. Large quantities of water pass through aquaporins. b. Charged ions, including Na+ and K+ require channel proteins to move through the membrane. c. Membranes may become polarized by movement of ions across the membrane. ENE-2.G.2 -Membrane proteins are necessary for active transport. ENE-2.G.3 -Metabolic energy (such as ATP) is required for active transport of molecules and/or ions across the membrane and to establish and maintain concentration gradients. ENE-2.G.4 The Na+ /K+ ATPase contributes to the maintenance of the membrane potential.

Describe similarities and/or differences in compartmentalization between prokaryotic and eukaryotic cells.

EVO-1.A.1 Membrane-bound organelles evolved from once free-living prokaryotic cells via endosymbiosis. EVO-1.A.2 Prokaryotes generally lack internal membrane-bound organelles but have internal regions with specialized structures and functions. EVO-1.A.3 Eukaryotic cells maintain internal membranes that partition the cell into specialized regions.

Describe the relationship between the functions of endosymbiotic organelles and their free-living ancestral counterparts.

Membrane-bound organelles evolved from previously free-living prokaryotic cells via endosymbiosis. "A Prokaryotic cell was consumed or engulfed by a larger cell. For some unknown reason, the prokaryotic organelle was not consumed. Such lack of consumption would later lead to both cells forming a mutualism, receiving surviving benefits from each other. Over time, the newly combined organelle would develop into the complex eukaryotic cell of today. The endosymbiotic theory has been widely accepted as one of the possibilities of the origins of mitochondria, chloroplasts, and other eukaryotic organelles and cells." basically, the organelle and the host had a beneficial relationship so the host did not consume the organelle

Explain how specialized structures and strategies are used for the efficient exchange of molecules to the environment.

Organisms have evolved highly efficient strategies to obtain nutrients and eliminate wastes. Cells and organisms use specialized exchange surfaces to obtain and release molecules from or into the surrounding environment.

Describe the roles of each of the components of the cell membrane in maintaining the internal environment of the cell.

Phospholipids have both hydrophilic and hydrophobic regions. The hydrophilic phosphate regions of the phospholipids are oriented toward the aqueous external or internal environments, while the hydrophobic fatty acid regions face each other with the interior of the membrane Embedded proteins can be hydrophilic, with charged and polar side groups, or hydrophobic, with nonpolar side groups.

Describe the mechanisms that organisms use to transport large molecules across the plasma membrane.

The process of endocytosis and exocytosis require energy to move large molecules into and out of cells -a. In exocytosis, internal vesicles fuse with the plasma membrane and secrete large macromolecules out of the cell. -b. In endocytosis, the cell takes in macromolecules and particulate matter by forming new vesicles derived from the plasma membrane. (Endocytosis is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane, and bringing it into the cell. Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell.)

Explain how the structure of biological membranes influences selective permeability.

The structure of cell membranes results in selective permeability, Selective permeability is a direct consequence of membrane structure, as described by the fluid mosaic model. The phospholipids are tightly packed together, and the membrane has a hydrophobic interior. This structure causes the membrane to be selectively permeable. A membrane that has selective permeability allows only substances meeting certain criteria to pass through it unaided.

Explain how concentration gradients affect the movement of molecules across membranes.

Water moves by osmosis from areas of high water potential/low osmolarity/low solute concentration to areas of low water potential/high osmolarity/high solute concentration.

Describe the structure and/or function of subcellular components and organelles. Explain how subcellular components and organelles contribute to the function of the cell.

https://quizlet.com/442801657/cell-structure-and-function-describe-the-structure-and-or-function-of-subcellular-components-and-organelles-flash-cards/

Explain how internal membranes and membrane-bound organelles contribute to compartmentalization of eukaryotic cell functions.

internal membranes facilitate cellular process by minimizing competing interactions and by increasing surface areas where reactions can occur

Explain the effect of surface area-to-volume ratios on the exchange of materials between cells or organisms and the environment.

the surface area to the volume ratio gets smaller as the cell gets larger. Thus, if the cell grows beyond a certain limit, not enough material will be able to cross the membrane fast enough to accommodate the increased cellular volume. ... That is why cells are so small.