cell molec

All living cells

share the same basic chemistry.

The inner membrane of the mitochondrion when examined with transmission electron microscopy appears _

folded with a large surface area to allow energy production (ATP synthesis) to take place.

Archaea and bacteria are both prokaryotes. They however distinguish themselves by:

the composition of the membrane

The organelle shown in the figure is the ___________ and one of its main functions is to______

Golgi apparatus; package and modify proteins, such as glycosylation, for secretion

Living cells differ from non-living cells because they are

self-replicatory.

The defining property that differentiates prokaryotic cells from eukaryotic cells is their

lack of a nucleus

The cellular process by which vesicles are secreted from cells is called:

exocytosis.

Which cell type has a long, branched structure that requires many connections to be made with neighboring cells?

nerve

The main function of the nucleus is to

house the DNA and ribosome synthesis machinery.

Which cell component is indicated in the figure below by the line labeled as number "3" (green) ?

nuclear envelope

Substances that do not form polar bonds are likely to be:

hydrophobic

A molecule with a large number of polar covalent bonds is likely to

be highly soluble in water.

What is the function of proteins inside cells?

they can serve as structural support, they can play a role in ligand recognition and signal transduction, &
they can reduce bacterial loads through forming barriers on cells

Which of these sugar molecules is NOT a monomer:

sucrose (monomers are ribose, glucose, and fructose)

Hydrolysis is________to _____molecular bonds.

addition of water - break

Which carbohydrate is NOT found in plants?

glycogen (found in plants is cellulose, starch, and pectin)

Where are glycoproteins mainly found?

bound to the outer plasma membrane

Long polymers are made from single subunits in cells using a ___________ reaction, which ___________ water.

condensation; releases

Triacyglycerols are ______

the most common fat storage molecules in cells

The beginning of a peptide chain is called the____terminus whereas the end of the peptide chain is called the___terminus.

N, C

Gibbs free energy is more likely negative when_____

entropy increases and enthalpy is low

Energy carriers are activated__

during the breakdown of molecules

 Gibbs free energy is negative when___

bonds are broken

An enzymatic reaction will most likely proceed if_____

the activation energy is lower than the energy expended to promote a reaction.

𝚫G indicates__

the change in a reaction from substrate to product

Equilibrium refers to a state where____

reactants and products do no longer change

The 2nd law of thermodynamics stipulates that____

entropy increases

In Catabolism, molecules are____whereas in Anabolism molecules are_______

broken down; synthesized

 Enzymes__

lower the activation energy without participating in the reaction between two reactants leading to a product.

Which of the molecules below are activated carriers?

NADH, NADPH, & ATP

An antibody interacts with an antigen through_

its heavy and light chain variable region

The first amino acid to be discovered was__

Asparagine from Asparagus in 1806.

A glycoprotein _

may participate in viral transfection, is assembled in the Golgi apparatus, locates within the plasma membrane with the sugar moeity facing to the extracellulars space.

What is the difference between a peptide and a protein?

Peptides are made up of linear amino acid chains.

Which of the following levels of protein structure involves the interaction of more than one protein into a multi-complex structure?

quaternary

Hydrogen bonding between NH and C=O groups of every 4th amino acid within the polypeptide backbone results in which type of folding pattern?

α helix (D)

Which of the following represents secondary structures in a protein?

a-helix

A protein can interact with water and lipds because____

it has polar and hydrophobic amino acids

The figure below shows a depiction of an antibody. Which label correctly identifies the region(s) of the antibody that contains variable amino acids for binding of a specific antigen?

A

Beta sheets adopt___

coiled formations, antiparallel orientations, or parallel confirmations.

The function of a feedback mechanism is to

turn on/off the synthesis of a gene or product.

Which of the following is true about a negative feedback loop?

The last enzyme in a chain of enzymatic reactions signals to a previous enzyme to stop the enzymatic reaction.

Which of the following is INCORRECT regarding how enzymes lower the activation energy of a reaction?

Enzymes reduce the free energy of the products of the reaction. (Correct: Enzymes encourage the substrates to change shape toward a transition state that favors the reaction, Enzymes align substrates to promote a reaction between them, & Enzymes rearrange electrons in the substrates in a way that favors the reaction.)

How does phosphorylation of a protein affect its activity?

could increase or decrease the activity

Disulfide bonds stabilize protein shape outside the cell by__

covalent bonds between cysteines.

What are glycochains used for by cells?

All of the above: They form mucus in the intestine to transport food molecules, They serve as cell surface recognition factors, They create structural support for plant cells

How does binding of a signaling molecule to its receptor affect its activity?

All of the above: Binding may activate the protein, Binding may inactivate the protein, Binding may change its conformation.

Shown below is the ATP hydrolysis cycle of a motor protein. What sentence BEST describes the state of the motor protein in "C"?

The hydrolysis of ATP to ADP caused a conformational change in the protein.

Which method is used for separating proteins based on specific interactions with other molecules?

affinity chromatography

The word "nucleoside" refers to____

the nitrogen base and sugar ring

Which of the following is found at the ends of eukaryotic genomes?

telomeres

Which of the following specialized DNA sequences provides an attachment point for the segregation of duplicated chromosomes?

centromeres

The technique whereby DNA is amplified is called________

PCR

Shown below is a schematic of an interphase chromosome. Which region is most likely to contain the highest density of genes?

B

Which of the following is a function of the protein component of chromosomes?

It packages the DNA strands.

The description of the DNA double helix was__

a combined effort of multiple scientists including Watson and Crick, Wilkins, and Franklin.

___________ is a sequence of DNA that contains the information required for making a particular functional RNA or protein.

A gene

The nucleolus__

assembles ribosomal RNA and proteins into ribosomes from 10 chromosomes that form a loop structure at their tip

Karyotyping refers to__

chromosomal staining and analysis

Which of the following describes the chromosomal makeup of a somatic cell of a human biological male?

22 pairs of autosomes + 1 X chromosome + 1 Y chromosome

How does Polymerase help maintain the accuracy of DNA replication?

DNA polymerase can cut out improperly base-paired nucleotides and add the correct one during synthesis.

The bonds that link two DNA strands together are

hydrogen bonds

What is the name of the DNA sequence where replication begins?

replication origin

Which double-strand break repair mechanism is a simple ligation mechanism?

nonhomologous end joining

What is the function of a topoisomerase in DNA replication?

It relieves the tension in DNA strands

Shown below is a replication bubble. At which location is the DNA polymerase adding nucleotides in a continuous manner

A and D

The sequence at which DNA replication begins tends to have which characteristic?

AT-rich

The energy for the polymerization reaction in DNA synthesis is powered by

the breaking of high-energy phosphate bonds in the deoxynucleotides.

If a stretch of DNA on the parental strand of a replicating chromosome has the sequence 5′–AGCTCGATCGGCTA–3′, what will the sequence of the newly synthesized strand made from this stretch of template be?

3′–TCGAGCTAGCCGAT–5′

How are the primers from which DNA synthesis starts different from the DNA itself?

The primers are made up of RNA not DNA.

At which step of gene expression can cells amplify the number of copies of a protein made from a single gene?

both transcription and translation

Export of RNA from the nucleus requires the RNA to have which characteristic(s)?

5′ cap and poly-A tail

The splicing of introns out of an mRNA molecule is catalyzed by

RNA molecules that base pair with the splice sites to promote intron removal, called the splicesome.

Why does RNA polymerase make more mistakes than DNA polymerase?

RNA polymerase does not have proofreading activity

How do tRNAs become attached to the correct amino acid?

aminoacyl-tRNA synthetases

What is the benefit of protein synthesis in polyribosomes?

More protein can be produced from a single RNA

Which type of RNA is converted into protein for performing its cellular function?

mRNA

Which nucleic acid often base pairs with itself to fold into complex three-dimensional shapes in the cell?

RNA

The catalytic sites for peptide bond formation during translation is found in which part of the ribosome?

large subunit RNAs

The reading frame to use for translating an mRNA into functional protein is determined by the

location of an AUG.

Mutations in which of the following elements would abrogate RNA polymerase’s ability to activate gene expression?

promoter

A housekeeping gene is a gene whose cellular function is

important for processes found in all cell types.

The figure below depicts which of the following mechanisms that cells use to maintain their identity through cell divisions?

positive feedback

The regulatory control of a gene product after transcription is called

post-transcriptional control.

Excess amounts of the amino acid tryptophan result in downregulation of the expression of the enzymes required for its synthesis due to

the repressor binding to the operator.

In the cell, enhancer sequence functions are limited in their range of action by the formation of ___________ that hold specific genes and enhancers in close proximity.

loops

Which of the following statements is correct regarding ATP driven pumps?

Eukaryotic cells contain a variety of ATP driven pumps including Na⁺/K⁺ ATPase, Ca⁺⁺ ATPase and H⁺ ATPase.

Noncoding RNAs include all of the following EXCEPT

mRNA (true for: rRNA, tRNA, regulatory RNAs)

MicroRNAs block the expression of a specific gene product by binding to the ___________ and inhibiting ___________

mRNA; translation

Transplanting the nucleus of an epithelial cell into an egg cell lacking genetic information leads to the formation of

a normally developing embryo.

How do retroviruses work?

they carry RNA that is transcribed into DNA for genomic integration using reverse transcriptase

A SNP is_____

a single nucleotide polymorphism which causes slighlty different traits in individuals.

Germline mutations that are deleterious are likely to

be lost from a population.

Which of the following mechanisms for genetic change involves the acquisition of genetic material from another organism?

horizontal transfer

What is a defining difference between viruses and mobile genetic elements?

Viruses can leave the cell and move to other cells and organisms; mobile genetic elements generally just move around the genome within in a cell.

A relatively small number of ________gave rise to eukaryotic protein diversity.

exons

A mutation in the ___________ of the gene encoding the enzyme lactase enables expression of this gene in adults.

regulatory sequence

How do gene duplications arise?

DNA replication causes misalignment of repetitive sequences which then leads to unequal crossing over

Mobile genetic elements___

encode the components they need for movement

The total size of the human genome is approximately ___________ base pairs

3.2 billion