CME 480- Cellular Biology

Antonie van Leeuwenhoek was the first to ___

observe bacteria and protozoa using a microscope

FTIR uses radiation in this wavelength range ___

mid-infrared

Bone formation and resorption depend on the relative activities of which two cell types?

Osteoblasts and osteoclasts

Hans Christian Gram initially developed his staining technique to visualize ___ in the lung tissue of pneumonia patients

cocci

The Golgi apparatus is primarily responsible for:

redirecting proteins for different fates

Red blood cells are disk-shaped, highly differentiated cells filled with this protein, which transports oxygen

hemoglobin

___ are star shaped cells whose endfeet are crucial in the establishment and maintenance of the blood brain barrier (BBB)

Astrocytes

Mitochondria drive numerous energy-requiring activities, most notably the synthesis of ___

ATP

Using a device designed by ___, Irving Langmuir perfected the apparatus now known as the Langmuir trough for studying monolayers

Agnes Pockels

Prokaryotes differ from eukaryotes in that the former:

have no nucleus, have no membrane-bound organelles, lack a cytoskeleton

Neurodegenerative disorder such as Alzheimer's are believed to result from faulty ___ of specific proteins

folding

___ form a myelin sheath in peripheral nerves

Schwann cells

Hematopoietic stem cells are known as:

universal blood stem cells

What was Frits Zernike's most notable contribution to science, for which he was honored the Nobel Prize in Physics in 1953?

invention of the phase contrast microscope

Multiple sclerosis (MS) in an inflammatory condition that involves the loss of ___ around axons

myelin

Match the following cell types with the tissues in which they are usually found:

___ 1. Cartilage A. Fibroblasts

___ 2. Fat tissue B. Osteoblasts

___ 3. Bone C. Chondrocytes

___ 4. Connective tissue D. Adipocytes

4

3

2

1

Members of the white blood cell group include:

polymorphonuclear cells, monocytes, neutrophils

The ___ is a structure in the cell responsible for the synthesis, sorting and folding of proteins

ER

These cells are responsible for constructing the type of connective tissue found in skin and tendons

fibroblasts

One of the main roles of the nucleus is:

controlling gene expression

The organelles of hair cells that detect fluid motion in animals for various functions, including hearing and balance, are called ___

stereocilia

Which membrane-bound organelle of the cell contains specialized enzymes used to disrupt chemical bonds and acts as a "destroying body"?

lysosome

A molecule that has both hydrophilic and hydrophobic parts is ___ in nature, which is characteristic of phospholipid bilayers

amphipathic

Ribosomes are organelles that are used to help form ___

proteins

Ribosomes can be scattered in the cytoplasm or bound to the ___

endoplasmic reticulum

The ___ is made up of macromolecules outside cells that support their structure and perform various intercellular functions

extracellular matrix

Usually found in newborns or hibernating animals, ___ dissipates most of the energy produced by food as heat

brown adipose tissue

Integral proteins, such as channel proteins, are ___ proteins that span the thickness of the cell membrane

transmembrane

During endocytosis, the lysosome and the vesicle it endocytoses combine to form a(n) ___

endosome

All of the following are functions of the cytoskeleton EXCEPT:

ATP synthesis

Which of the following statements about lysosomes is/are true?

They contain lysozymes that can disrupt chemical bonds, their membrane protects the other contents of the cell, they form an endosome with the vesicle that is being endocytosed

Whereas light microscopes are capable of resolving structures of a few hundred nanometers, electron microscopes can resolve down to 0.2 nanometers

True

Intermediate filaments aid in providing structure to cell shape and can come in many different types. Match the following intermediate filament types to where they can usually be found:

___ 1. Parts of the nuclear envelope

___ 2. Developing neurons, stem cells of the central nervous system

___ 3. Muscle cells

___ 4. Skin cells

___ 5. Fibroblasts, smooth muscle cells, and white blood cells

___ 6. Mature neurons

A. Keratin

B. Vimentin

C. Desmin

D. Neurofilament

E. Lamin

F. Nestin

6

3

2

1

5

4

Using X-ray diffraction, ___ discovered that DNA is a double helix, which was demonstrated in the famous "Photo 51"

Rosalind Franklin

All of the following may be found in the cytosol EXCEPT:

cilia

Briefly explain why mitochondrial DNA is a better forensics tool than nuclear DNA

Mitochondrial DNA is maternally inherited, allowing for individuals to be identified with maternal lineage. In addition, mtDNA does not degrade as quickly as nuclear DNA so investigators would have more time to identify the individual

The medical diagnosis PET stands for:

positron emission tomography

Who was awarded the Nobel Prize for his discovery of the positron?

Carl Anderson

Brown adipose tissue (BAT) contains a large number of this organelle:

mitochondrion

Peroxisomes are ubiquitous in almost all eukaryotes

True

Programmed cell death, where the cell is broken down in a controlled manner, is known as:

apoptosis

The phenomenon whereby a phosphate is transferred to an animo acid is called:

phosphorylation

Chemical messengers that act on neighboring cells, such as in the case of neurotransmitters that are secreted by one neuron and uptaken by a second neuron, are classified as:

paracrine

Tamoxifen acts as an estrogen antagonist in the breast, which means that it is capable of ___ the receptor

blocking

Chemical messengers that act on neighboring cells are classified as:

paracrine

All of the following are true statements related to apoptosis EXCEPT:

During apoptosis, intact pieces of the cell are removed by epithelial cells without triggering an inflammatory response

Which of the following statements is/are true about steroid hormones?

They bind to intracellular receptors, they have a profound effect on physiological functions, they affect the transcription process of genes by binding to promoters, they freely pass the plasma membrane of the target cell

An agonist partakes in ligand binding, although it prevents receptor activation and blocks ligand activity

False

Uncontrolled cell rupture and inflammation, usually caused by cell injury, is known as:

necrosis

What increases transcription by changing the structure of nucleosomes?

coactivator proteins

___ is the state of dynamic constancy and requires constant communication among cells via messages

homeostasis

In addition to obtaining high-resolution microscopy images of the endoplasmic reticulum, ___ also discovered microtubules, which are involved in supporting the cytoskeleton

Keith Roberts Porter

It is believed that disruptions in endoplasmic reticulum (ER) homeostasis can activate unfolded protein response, which may result in loss of beta cells and the physiological condition known as:

diabetes

In a 2018 study by Cortes et al., it was shown that Tamoxifen reduces myosin activation and impairs force generation in these cells:

hepatic stellate cells

Histone acetyltransferase (HAT) adds acetyl groups to lysine residues in histone, resulting in the ___ of DNA

loosening

Whereas M1 macrophages are associated with ___ functions, M2 macrophages have mostly ___ functions

inflammatory/anti-inflammatory

All of the following are true of nuclear receptors EXCEPT:

they do not impact the frequency or accuracy of transcription initiation

The 3 groups of ion channels are:

ligand-gated, voltage-gated, mechanically gated

Mechanically gated receptors transduce a mechanical stimulus into a ___ response

physiological

The ability of ion channels to conduct only certain ions across the membrane is called:

selectivity

Eccles, Hodgkin and Huxley were awarded the Nobel Prize in Physiology or Medicine in 1963 for their work on understanding how electrical pulses are generated and transmitted in nerve cells of ___

squids

The electric potential difference between the inside and outside of the plasma membrane is referred to as:

membrane potential

The small (20-50 nm) gap between two neurons engaged in neurotransmission is called the:

synapse

Chemical substances involved in the transmission of nerve impulses are known as:

neurotransmitters

One of the most widely studied neurotransmitters, ___ is involved in the transmission of nerve impulses to skeletal muscles

acetylcholine

Excess amount of caffeine can cause the downregulation of ___ receptor, leading to nerve cell hyperactivity

GABA

Excess amounts of this excitatory neurotransmitter, which is important in memory, learning and cognition, are normally recycled by glial cells

glutamate

A 2021 study showed that supplementation with melatonin restored ___ levels in Zebrafish brain

GABA

___ membrane receptors are protein complexes that form a channel through the cell membrane

Ionotropic

In the brains of Alzheimer's disease (AD) patients, glutamate uptake by ___ is interrupted, leading to neuronal swelling and cell death

astrocytes

It has been postulated that branched chain amino acids (BCAAs) may help repair neurodegenerative conditions such. BCAAs refer to these three amino acids

Leucine, Isoleucine, Valine

G-protein coupled receptors (GPCRs) are known to bind ___ nucleotides

guanine

After a G-protein is activated, effectors are turned on and downstream second messengers such as ___ are activated

cAMP

The process of limiting repeated stimulation by blocking active receptors from being turned on is known as:

desensitization

In the Alzheimer type of senile dementia, acetylcholine-releasing neurons undergo extensive degeneration. One therapeutic approach is to use ___ blockers to increase acetylcholine release

acetylcholine esterase

During the activation of protein kinase-associated receptors, ___ kinases phosphorylate intracellular target proteins, triggering downstream signaling cascades

tyrosine

___ is the first discovered member of the receptor tyrosine kinase superfamily and is closed related to vascular endothelial growth factor (VEGF)

Epidermal growth factor (EGF)

According to the Watson-Crick base pairing pattern of nucleotides, the base pair of adenine and thymine has two hydrogen bonds. In contrast, cytosine and guanine have ___ hydrogen bond(s) between them

three

An entire collection of DNA is referred to as the:

genome

Deoxyribonucleic acid, also known as DNA, is a polynucleotide chain that comprises four different deoxynucleotides. Which of the following is NOT a component of the deoxynucleotide compounds?

ribosome

Exons are coding regions of genes that remain in the ___ following posttranscriptional processing

RNA

It is estimated that there are ___ genes in humans

25,000

The sequence of DNA that extend between the coding exons are known as ___, and they help to separate the exons into distinct domains with functional purposes

introns

The process of cooling melted DNA is known as:

annealing

Nonhistone DNA proteins consist of transcription factors, polymerase, hormone receptors, and other nuclear enzymes

True

___ are DNA-binding proteins involved in maintaining the compacted structure of chromatin

histones

It is expected that this fraction of DNA molecules are single stranded at the DNA's melting temperature

1/2

Both gamma rays and X-rays can ___ DNA strands

sever

DNA replication is a semiconservative process, which means that newly synthesized daughter strands remain associated with their respective ___ strands

template

During DNA translation, ___ serves as the link between an amino acid and the mRNA

tRNA

During the initiation phase of DNA transcription, the promoter region functions as a ___ site for RNA polymerase to bind

recognition

DNA polymerase ensures the fidelity of replication by repairing damaged and mismatched DNA

True

Newly synthesized mRNA contains exons, which code for proteins, and non-coding introns, which are removed by the ___

spliceosome

The product of transcription is:

mRNA

This enzyme is responsible for unwinding the double-stranded DNA at the replication fork

helicase

What is the product of translation?

polypeptide

When a stop codon is encountered, the ___ process is terminated

translation

During mitosis, all of the following occur EXCEPT:

The centrioles are reformed as the chromosomes are decondensed and spindle fibers are dispersed during telophase

Specific cells, such as those found in heart tissue or nervous tissue, become terminally differentiated. This means that they no longer proliferate and are permanently locked in the cell cycle's resting phase. These cells are in the ___ phase

G0

During the ___ phase, cells respond to various signals for growth or differentiation and prepare for DNA synthesis

G1