Cell Bio - Final Exam

Which of the following hydrocarbon tail would yield the most highly mobile phospholipid (listed as number of carbons and number of double bonds, respectively)?

15 carbons with 2 double bonds

Given the sequence of a coding strand: 5' - GCATTCGTGGGTAG - 3' Give the sequence of the mRNA and label the 5' and 3' ends.

5'- GCAUUCGUGGGUAG -3'

Which of the following compounds can be a potential anti-cancer drug?

A compound that activates Ras-GAP

Which of the following statements is FALSE?

A histone core contains two of each of the core histones (H1, H2, H3, H4).

Researchers studying vesicular transport assembled several transport components in vitro (in a test tube). They set up the stabilized microtubules, then added vesicles and kinesin. When they put everything together, there was no movement of transport vesicles along microtubule. What were they missing?

ATP

What would be the consequence of inactivation of E2F?

Cells would be unable to enter the S phase.

Which of the following statements about the cytoskeleton is FALSE?

Covalent bonds between protein monomers hold together cytoskeletal filaments.

In DNA replication the lagging strand is synthesized discontinuously at the replication fork because

DNA polymerase can polymerize nucleotides only in the 5'-to-3' direction

If the anaphase promoting complex (APC) is temperature sensitive (active at 30C, but inactive at 40C), shifting to the new higher temperature (40C) at the start of M phase would prevent which of the following?

Degradation of securin and separation of sister chromatids.

Which of the following statements about antibodies is TRUE?

Disulfide bonds are formed between the polypeptide chains

You use GFP tag to track a protein that will ultimately be secreted from the cell. If all is functioning well, in which order (from first to last) do you expect to find the protein in the cell until it is secreted?

ER → Golgi → secretory vesicle → outside of the cell

Which of the following statements about enzyme is FALSE?

Enzymes speed reactions by decreasing G (energy difference between reactant and product).

Which of the following statements is TRUE?

Extracellular signal molecules that are hydrophilic usually bind to a cell-surface receptor to signal a target cell.

Cell movement involves the coordination of many events in the cell. Which of the following phenomena is NOT required for cell motility?

Influx of Ca2+ into cytoplasm.

Which of the following is FALSE of the sodium-potassium pump?

It transports 2 sodium ions out of the cell and 3 potassium ions into the cell each time.

Which group of enzymes control protein activate by adding phosphate groups to the protein?

Kinase

Which of the following would you expect to see in a cell that has been exposed to colchicine?

Mis-organized endomembrane system

Which of the following statements about genome is FALSE?

Most of the human genome code for proteins.

Which of the following statement is TRUE?

New phospholipids are synthesized at the cytosolic side of ER

Which of the following transcription factors is needed to convert an adult cell into an induced pluripotent stem (iPS) cell?

Oct4, Klf4, sox2

Which of the following statements is TRUE?

Phospholipids have both hydrophilic and hydrophobic components.

A mutation on securin prevents its ubiquitynation and degradation. In a cell containing this mutation, which of the following phenotypes can be predicted?

Sister chromatids will not be segregated after metaphase.

Which of the following microscopy has the highest resolution?

TEM

Which of the following statements about fluorescence microscopy is FALSE?

The excitation wavelength of GFP is longer than its emission wavelength

Which of the following statements about membrane-enclosed organelles is TRUE?

The membrane of nucleus is always continuous with the membrane of ER

What will NOT happen if too many misfolded proteins are accumulated in the ER?

The misfolded proteins will be packaged and secreted outside to keep the cell healthy.

What would happen if you add a ER-specific signal sequence to the amino-terminal end of a normally cytosolic protein?

The protein will be delivered to the ER and fully synthesized in ER

Which of the following statements is FALSE?

The sequence of the atoms in the polypeptide backbone varies among different proteins.

Which of the following statements about protein transport to mitochondria is TRUE?

The signal that directs a protein to mitochondria is always cleaved off from the final folded protein.

Which of the statements below about intermediate filaments is FALSE?

They are made of globular subunits.

Which of the following means of transport would most likely be used for moving an amino acid from a low concentration on the outside to a high concentration on the inside of a cell?

active transport though a transporter

Which of the following is NOT one of the pathways activated by RTKs?

cAMP-PKA

A multipotent cell _________.

can give rise to some cell types in the body

An adult hematopoietic stem cell found in the bone marrow ______________________.

can undergo self-renewing divisions for the lifetime

The activity of a protein can be posttranscriptionally regulated by any of the methods except .

controlling gene expression

A cell with mutated lamins that cannot be phosphorylated in M phase will be unable to

disassemble its nuclear lamina at prometaphase.

During __________________ signaling, the signal travels through the bloodstream acting on a target cell far from the hormone secreting cell.

endocrine

The members of the steroid hormone receptor family __________________.

interact with signal molecules that diffuse through the plasma membrane.

A malignant tumor is more dangerous than a benign tumor because its cells ________________.

invade other tissues

Researchers observed disorganized heterochromatin in the cells of a mutant. Which of the following protein is most likely mutated?

lamin

In a muscle cell, which internal organelle would you expect to be particularly abundant?

mitochondria

Which of the following proteins can move cargos through an actin filament?

myosin

Embryonic stem cells are such a powerful possible treatment for disease because they are______.

pluripotent

When a terminally differentiated cell in an adult body dies, it can typically be replaced in the body by a stock of ________.

proliferating precursor cells that are derived from adult stem cells

Which gene mutation give rise to unchanged amino acid sequence in a protein?

silent mutation

Which type of RNA in the following controls mRNA splicing?

snRNA

Which of the following molecules can help assemble a signaling complex?

some types of cell surface receptors, a type of phospholipid, some scaffold proteins

Which of the following molecule has the highest permeability to plasma membrane?

steroid hormone

Progression through the cell cycle requires a cyclin to bind to a Cdk because _________.

the binding of a cyclin to Cdk is required for Cdk enzymatic activity

To study a protein that controls development, which of the following model organism may NOT be chosen?

yeast

Acetylcholine controls the contraction of skeleton muscle and smooth muscle using different signaling pathways. Which mechanism is shared by these two pathways?

Ca2+ release from sarcoplasmic reticulum