Chapter 7.2 & 7.4 Flashcards
What is the function of the nucleus?
The nucleus is the control center of the cell. The nucleus contains nearly all the cell’s DNA and, with it, the coded instructions for making proteins and other important molecules.
Distinguish between cytoplasm and cytosol.
The cytoplasm is the portion of the cell outside the nucleus. It’s everything inside a cell but the nucleus. The cytosol is the jelly like substance in between organelles.
What is the name of the membrane that surrounds the nucleus?
Nuclear envelope or nuclear membrane.
What is the function of nuclear pores?
Nuclear pores allow material to move into and out of the nucleus.
What two structures are found inside the nucleus?
DNA (chromosomes and chromatin) and Nucleolus.
What structure makes ribosomes?
The Nucleolus makes ribosomes.
What is a vacuole?
A large, saclike, membrane-enclosed structure. Vacuoles store materials like water, salts, proteins, and carbohydrates. In many plant cells, there is a single, large central vacuole filled with liquid.
What is the function of a lysosome?
Lysosomes break down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell. They are also involved in breaking down organelles that have outlived their usefulness. Lysosomes perform the vital function of removing “junk” that might otherwise accumulate and clutter up the cell.
What is the difference between a microfilament, microtubule and cytoskeleton?
Microfilaments are threadlike structures made up of a protein called actin. They form extensive networks in some cells and produce a tough flexible framework that supports the cells. They also help the cells move.
Microtubules are hollow structures made up of proteins known as tubulins. In many cells, the play critical roles in maintaining cell shape. Microtubules are also important in cell division, where they form a structure known as the mitotic spindle, which helps to separate chromosomes.
The cytoskeleton helps the cell maintain its shape and is also involved in movement.
What are centrioles and when do they serve a purpose?
Centrioles are organelles formed from tubulins. Centrioles are located near the nucleus and help organize cell division. Centrioles are not found in plant cells.
Distinguish between free and attached ribosomes.
Ribosomes are small particles of RNA and protein found throughout the cytoplasm in all cells. Attached ribosomes are found on the Rough ER and free ribosomes are located in the cytosol.
Distinguish between rough and smooth ER.
ER stands for endoplasmic reticulum and it’s where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell.
Rough ER - portion of the ER involved in synthesis of proteins. given its name because of ribosomes on its surface. Proteins made on the rough ER include those that will be released, or secreted, from the cell as well as many membrane proteins and proteins destined for lysosomes and other specialized locations within the cell.
Smooth ER - given name because ribosomes are not found on its surface. The smooth ER contains collections of enzymes that perform specialized tasks, including the synthesis of membrane lipids and the detoxification of drugs.
What does the Golgi Apparatus do to the proteins it receives from the rough ER?
As proteins leave the rough ER, molecular address tags get them to the right destinations. As these tags are read by the cell, the proteins are bundled into tiny vesicles that bud from the ER and carry them to the Golgi apparatus. The Golgi apparatus modifies, sorts, and packages proteins and other materials from the ER for storage in the cell or release outside the cell.
Compare chloroplasts and mitochondria in terms of structure and function. (Short answer question)
Chloroplasts and mitochondria can both be found in plants. They are both similar in structure because they both are surrounded by two membranes. They are both the power plants of the cells. Chloroplasts and mitochondria contain their own genetic information in the form of small DNA molecules, and this has led to the endosymbiotic theory, or the idea that they may be descended from independent microorganisms. However, chloroplasts and mitochondria are very different. Chloroplasts capture the energy from sunlight and convert it into food that contains chemical energy in a process called photosynthesis. Mitochondria covert the chemical energy stored in food into compounds that are more convenient for the cell to use.
Explain the endosymbiotic theory.
Lynn Margulls suggested that chloroplasts and mitochondria may be descended from prokaryotes.
