Bi 111 Exam 2 2023

Label the picture

A=Glycolipid B=Glycoprotein C=Cholesterol D=Phospholipid bilayer

_____ proteins are embedded in biological membranes, whereas ______ proteins are associated with surface regions of biological membrane.

integral; peripheral

What property of cell membranes is affected by this change, and how is this property affected?

Membrane fluidity is increased in the shift from condition 1 to condition 2.

Which of these statements can be used to explain the importance of the cell membrane to cell survival?

Cell membranes are selectively permeable with respect to molecules and ions.

Which of the conditions will result in the greatest rate of diffusion of X into area A?

The concentration of X in A is 10 mM; the concentration of X in B is 2 M

Which statement about diffusion is false?

Simple diffusion depends on specific carrier or channel proteins,

Osmosis is….

the movement of water across selectively permeable membranes.

A unicellular organism used to salt water is placed in freshwater. What is the result?

Water moves into the cell, causing it to burst.

An increased need for a particle present in a high concentration within the cell then extracellular fluid would result in….

active transport, which moves molecules opposite of diffusion.

What would be absent from a diagram illustrating the mechanism for lactose?

The direct use of ATP to transport lactose.

Which molecule will move across the phospholipid bilayer the quickest with no protein associated with the bilayer?

NH3

Phagocytosis, pinocytosis, and receptor-mediated endocytosis all involve…

invagination of the cell.

Receptor-mediated endocytosis….

results in the formation of clathrin-coated vesicles.

Villi of the small intestine are lined with epithelial cells that absorb nutrients from digested food on one side and transfer them on the other. Which cell would be most effective?

Cell A because it has a larger surface area to volume ratio than Cell B.

Which structure is directly related with the movement of organelles within a cell?

Microtubules

Correct sizing of cytoskeletal elements?

microtubules>intermediate filaments> microfilaments

What is wrong with this table?

The descriptions of relationships to cells should be flipped.

Why is compartmentalization important for normal cell function?

The cell carries out many functions that can interfere with another if not separated.

How should you determine if a cell is a prokaryote or eukaryote?

Study the type of compartmentalization of functions within the cytoplasm.

Proteins are synthesized by ______ and the carbohydrates are added in the ______.

rough endoplasmic reticulum, golgi apparatus

Which is true for ATP?

The hydrolysis of ATP to ADP and Pi is an exergonic reaction.

Which example does not need ATP hydrolysis?

B-oxidation of fatty acids.

Give an example of a redox-reaction

R-CH=CH-CH3+H2O→←RCH2-CH(OH)-CH3

Which molecule as high energy bonds that can be oxidized to release enough energy to drive NADH and ATP synthesis from NAD+ and ADP?

C5H10O2

Glycolysis….

is a redox process

Which catabolic step has the greatest ATP produced?

Oxidative phosphorylation

Which statement about the citric acid cycle is true?

Takes place in mitochondrial matrix.

Conversion of NAD+ to NADH. NAD+ is…

reduced.

Fermentation….

results in the formation of lactic acid or ethanol.

A suspension of yeast supplied with glucose as its source of energy was transferred from an aerobic environment to an anaerobic one. The yeast must expend the same amount of energy to survive in both environments. Which result would you predict for the rate of glucose utilization and the rate of ethanol production after the transfer?

Both glucose usage and ethanol production would increase.

Which student do you agree with in terms of metabolism?

Student 5

Which statement best characterizes the properties of a photosystem?

A photosystem is a complex of pigments, proteins, and reaction center chlorophyll.

Which statement about asexual reproduction in flowering plants is true?

Asexual reproduction produces offspring that are genetically identical to parent.

In sexually reproducing organisms, the diploid phase of the life cycle begins at…..

fertilization.

Binary fission differs from eukaryotic division in that….

a spindle is involved in chromosome segregation in eukaryotic cells.

Which cellular event occurs outside of interphase?

The condensation of chromatin.

Which stage of mitosis includes the formation of kinetochores?

Prophase

After DNA replication each cell has _______ molecules of DNA called _______, that after separation are known as ________ chromosomes.

two; sister chromatids; unreplicated

The mitotic spindle….

is involved in creating the force needed for chromosome movement.

During mitosis, anaphase….

is the phase during which sister chromatids separate and move to opposite poles.

Cytokinesis….

involves the golgi apparatus in plants

In meiosis, as opposed to mitosis….

the pairing of homologous chromosomes occurs.

In meiosis II….

sister chromatids seperate.

Human cell has 23 pairs of chromosomes. The number of unreplicated chromosomes in a human following telophase II is….

23.

Homologous chromosomes experience crossing over during…

prophase I of meiosis.

Which statement about aneuploidy is true?

An individual with an extra chromosome is trisomic.

Polyploidy….

can be caused by polyspermy.

DNA replication occurs….

before both mitosis and meiosis.

According to the table, when does DNA double?

S phase

Which statement about CDK is true?

CDK bound to a G1/S cyclin can catalyze the phosphorylation of retinoblastoma protein.

What is a conclusion that can be drew from this data?

In fused cells, a substance in S cells that activates DNA replication can diffuse into the G1 nuclei.

Apoptosis….

is a genetically programmed series of events.