Cell Structure & Function

Objectives:

1.1 Understand the relationship between the structures and functions of cells and their organelles

1.1.1 Summarize the structure and function of organelles in eukaryotic cells (including the nucleus, plasma membrane, cell wall, mitochondria, vacuoles, chloroplasts, and ribosomes) and ways that these organelles interact with each other to perform the function of the cell

Unpacked:

•Identify these cell organelles in diagrams of plant and animal cells.

• Explain how the structure of the organelle determines it function. (Example: folded inner membrane in mitochondria increases surface area for energy production during aerobic cellular respiration).

• Summarize how these organelles interact to carry out functions such as energy production and use, transport of molecules, disposal of waste, and synthesis of new molecules. (Example: DNA codes for proteins which are assembled by the ribosomes and used as enzymes for energy production at the mitochondria).

1.1.2 Compare prokaryotic and eukaryotic cells in terms of their general structures (plasma membrane and genetic material) and degree of complexity

Unpacked:

•Proficiently use proper light microscopic techniques as well as determine total power magnification. The purpose is to use microscopes to observe a variety of cells with particular emphasis on the differences between prokaryotic and eukaryotic as well as plant and animal cells. While students are not expected to understand how scanning and electron transmission microscopes work, they should recognize that they reveal greater detail about eukaryotic and prokaryotic cell differences.

• Infer that prokaryotic cells are less complex than eukaryotic cells.

• Compare the structure of prokaryotic and eukaryotic cells to conclude the following:

o Presence of membrane bound organelles – mitochondria, nucleus, vacuole, and chloroplasts are not present in prokaryotes.

Ribosomes are found in both.

o DNA and RNA are present in both, but are not enclosed by a membrane in prokaryotes.

o Contrasts in chromosome structure – circular DNA strands called plasmids are characteristic of prokaryotes.

o Contrasts in size – prokaryotic cells are smaller.

1.2 Analyze the cell as a living system

1.2.1 Explain how homeostasis is maintained in the cell and within an organism in various environments (including temperature and pH).

Unpacked:

• Explain how cells use buffers to regulate cell pH and how cells can respond to maintain temperature, glucose levels, and water balance in organisms.

• Compare the mechanisms of active vs. passive transport (diffusion and osmosis).

• Conclude how the plasma membrane structure functions.

• Explain changes in osmotic pressure that occurs when cells are placed in solutions of differing concentrations.

4.2 Analyze the relationships between biochemical processes and energy use in the cell.

4.2.2 Explain ways that organisms use released energy for maintaining homeostasis (active transport).

Unpacking:

Conclude that energy production by organisms is vital for maintaining homeostasis and that maintenance of homeostasis is necessary for life. Examples: Active transport of needed molecules or to rid the cell of toxins; movement to avoid danger or to find food, water, and or mates; synthesizing needed molecules