Chapter 6 Flashcards
(28 cards)
Define a membrane-bound organelle, giving examples.
Membrane bound organelles are cellular structures that contain their own membranal sac/envelope. eg nucleus, mitochondria, chloroplasts.
Define cytoplasm and cytosol, explaining the difference between the two.
Cytosol is the semifluid, jelly like substance which the cell’s organelles are suspended in. The cytoplasm is the interior of the cell between the nucleus and plasma membrane.
Define Chromatin and chromosomes. Explain the relationship and difference between the two.
Chromatin is the complex form of the genetic material of an organism. However, DNA strands are long and can be great in length. Therefore the are tightly packed and condensed into chromosomes.
What is the lumen. State its function
To transport substances within cells.
What is a vesicle? State its function.
A tiny membranal sac that aids in transportation of cell contents/secretion of necessary enzymes.
Explain the structure and function of collagen
Collagen is a protein made of many fibers that provides strength and elasticity to cells.
What are proteoglycans? What do they do?
Proteoglycans are small core proteins bounded to chains of carbohydrates, acting as fillers between cells.
What are integrins?
Integrins are cell surface receptor proteins that help cells by notifying them of stimuli in the environment, ‘integrating changes within and outside the cell.” They link cytoskeletons with the extracellular matrix.
What are laminins?
Laminins are glycoproteins that link the integrins to the extracellular matrix.
What are common characteristics of cells?
All cells have cytosol, cytoplasm, plasma membranes and ribosomes.
What is the major type of microscopy used to identify cells?
Light microscopy. This utilizes focused light to magnify the image of the specimen.
What are some differences between prokaryotic and eukaryotic cells?
See bio scio.
What is the function of the nuclear envelope?
A double membrane that encloses the nucleus and protect the organism’s DNA.
What is the function of the nuclear lamina?
The nuclear lamina supports (mechanically) the nuclear envelope . It is a netlike structure of protein filaments.
What does the nucleolus do?
The nucleolus is responsible for the manufacture of ribosomal subunits which leave through the nuclear pores and join to form ribosomes in the cytosol.
What are nuclear pores? what is their function?
Nuclear pores are perforated holes in the nuclear envelope that allow for the net traffic of proteins and RNA within the nucleus and cytoplasm, done by its pore complex. They tend to be about 100nm in diameter.
How are ribosomes made? Explain their importance and function.
Ribosomes are the cellular components that carry out protein synthesis (Translation). They are made via the rRNA produced by the nucleolus. They are important as they aid in the specialization of proteins.
What is the main function of mitochondria?
Mitochondria are the main/major manufacturers of ATP in most organisms. While respiration can occur anaerobically, without oxygen, aerobic respiration that occurs in the mitochondria produces much more energy and ATP molecules, and therefore is much more efficient.
What is the main function of chloroplasts? Where are they found?
Chloroplasts are the sites of photosynthesis found primarily in the palisade layer of plant cells. They contain photosystems which trap light energy from the sun, converting it to usable chemical energy. This is important as the sun is the earth’s major energy source, and without chloroplasts, we wouldn’t be able to access this energy.
What is the rough ER? What is the smooth ER? State the functions of both and explain their differences.
The rough ER has bound ribosomes attached to its outer membrane. Its major function is the specialization of proteins (specifically secretory proteins).
The smooth ER has no outer ribosomes. It is responsible for a variety of functions: lipid synthesis, detoxification, storage of Ca2+ ions, metabolism of carbohydrates.
What is glycosylation? Where does it occur?
Glycosylation is the addition of a carbohydrate molecule. It occurs in the golgi apparatus
What is the Golgi apparatus? Why do we say its ‘directional’?
What are lysosomes? Why are their pH regulated to a certain number? What is the average pH in a lysosome?
Lysosomes are membranal sacs of digestive enzymes that aid in the breakdown of waste materials of the cells. Due to the presence of its enzymes, they need to have a regulated pH, to prevent the denaturation of these enzymes. Their pH range is usually between 4.5-5.
What are cytoskeletal filaments? What is meant by ‘dynamic’ filaments?
Cytoskeletal filaments are intermediate fibers that are wrapped together, producing shape and holding organelles in place. It is referred to as dynamic as they can be rearranged to change the cell shape and allow for cell movement.
