BIO BPP'21

At which of the following pH levels would a lysosome's enzymes function best?

5 Lysosomes are spherical structures that contain enzymes that function best under slightly acidic conditions (pH 4.5-5.0) and can break down most types of molecules, thereby acting as the waste disposal system of the cell by digesting unwanted materials.

Why is the rough ER called "rough"?

Because it is studded with ribosomes

Which of the following would be significantly increased by mutations affecting microtubule function?

Birth defects Mutations affecting microtubules would cause birth defects by impacting the ability for chromosomes to be "pulled apart" during anaphase of meiosis. Mucus buildup in the throat Mutations affecting microtubules would cause mucus buildup in the throat by inhibiting throat epithelial cells' ciliary action, which normally clears debris in the throat. Male sterility Mutations affecting microtubules could cause male sterility in at least two ways: 1) chromosomal nondisjunction might affect cellular functionality, and 2) flagellum dysfunction would inhibit sperm motility.

A loss-of-function mutation in a gene that codes for tubulin would most directly inhibit which of the following processes in meiosis?

Chromosome separation Chromosome separation during anaphase depends on the spindle, which is made of microtubules. Microtubules are composed of tubulin.

Of the options below, which of the following are typically multimeric? Select all that apply.

F-actin F-actin is the polymeric form of actin, meaning it is made of multiple actins polymerized together. F-actin F-actin is the polymeric form of actin, meaning it is made of multiple actins polymerized together. Lamin Lamin - an intermediate filament - is multimeric.

Secretory proteins are transported from the endoplasmic reticulum to the trans-face of the Golgi apparatus.

False: They are transported from the ER to the cis-face of Golgi apparatus.

Which of the following is a function of the rough endoplasmic reticulum?

Folding and modifying newly synthesized proteins

E. coli

In bacteria (such as E. coli), flagella are made of the protein flagellin, not microtubules.

Which of the following is a function of the smooth ER?

It synthesizes lipids. Detoxification

organelles are membrane-bound?

Mitochondria Rough ER Smooth ER

Which of the following is a function of the Golgi apparatus?

Packaging proteins that will leave the cell

How are peroxisomes and lysosomes different?

Peroxisomes are not packaged at the Golgi apparatus. Peroxisomes are organelles that break down a variety of compounds such as fatty acids and amino acids. These organelles also facilitate the detoxification of reactive oxygen species such as hydrogen peroxide. Lysosomes are organelles that possess hydrolytic enzymes that digest unwanted materials. Lysosomes are formed by pinching off as vesicles from the Golgi apparatus, but this is not true of peroxisomes.

Which of the following are most likely NOT potential functions of cytoskeletal capping proteins? Select all that apply.

Promoting cytoskeletal polymer degradation Promoting the Krebs cycle

Microtubules are found in cilia or flagella in which of the following cell types? Select all.

Sperm cells Sperm cells contain flagella. In eukaryotes, both cilia and flagella are composed of microtubules. Tracheal epithelial cells Tracheal and fallopian tube epithelial cells contain cilia. In eukaryotes, both cilia and flagella are composed of microtubules. Fallopian tube epithelial cells Tracheal and fallopian tube epithelial cells contain cilia. In eukaryotes, both cilia and flagella are composed of microtubules.

Kinesins

are the accessory proteins that carry neurotransmitter-containing vesicles to a neural synapse. move from the center of the cell towards the edge, including towards the plasma membrane and the synapse Dyneins travel in the opposite direction.