Diffusion

Selectively Permeable

A membrane that allows only certain substances to pass through.

Permeable

A membrane that allows something to pass through it.

Impermeable

A membrane that does not allow anything to pass through it.

all of the above

A mutation in the gene for a cyclin protein might result in which of the following? a.a cell with additional genetic material than normal b.cancer c.a cell with less genetic material than normal d.any of the above

equalibrium

A solution that has an equal concentration

Cell membrane

ALL materials enter and leave the cell through the ____.

d.pleuripotency, multipotency, oligopotency, unipotency

Arrange the following terms in order of increasing specialization: oligopotency, pleuripotency, unipotency, multipotency. a.multipotency, pleuripotency, oligopotency, unipotency b.pleuripotency, oligopotency, multipotency unipotency c.oligopotency, pleuripotency, unipotency, multipotency d.pleuripotency, multipotency, oligopotency, unipotency

b.integral proteins

Because they are embedded within the membrane, ion channels are examples of ________.

Transcription and DNA replication both involve the synthesis of nucleic acids. These processes share many common features—particularly, the similar processes of initiation, elongation, and termination. In both cases the DNA molecule must be untwisted and separated, and the coding (i.e., sense) strand will be used as a template. Also, polymerases serve to add nucleotides to the growing DNA or mRNA strand. Both processes are signaled to terminate when completed.

Briefly explain the similarities between transcription and DNA replication

b.osmosis; pinocytosis

Choose the answer that best completes the following analogy: Diffusion is to ________ as endocytosis is to ________. a.filtration; phagocytosis b.osmosis; pinocytosis c.solutes; fluid d.gradient; chemical energy

d.the water

Choose the term that best completes the following analogy: Cytoplasm is to cytosol as a swimming pool containing chlorine and flotation toys is to ________. a.the walls of the pool b.the chlorine c.the flotation toys d.the water

Peroxisomes and lysosomes are both cellular organelles bound by lipid bilayer membranes, and they both contain many enzymes. However, peroxisomes contain enzymes that detoxify substances by transferring hydrogen atoms and producing H2O2, whereas the enzymes in lysosomes function to break down and digest various unwanted materials.

Compare and contrast lysosomes with peroxisomes: name at least two similarities and one difference.

Transcription is really a "copy" process and translation is really an "interpretation" process, because transcription involves copying the DNA message into a very similar RNA message whereas translation involves converting the RNA message into the very different amino acid message. The two processes also differ in their location: transcription occurs in the nucleus and translation in the cytoplasm. The mechanisms by which the two processes are performed are also completely different: transcription utilizes polymerase enzymes to build mRNA whereas translation utilizes different kinds of RNA to build protein.

Contrast transcription and translation. Name at least three differences between the two processes.

an enzyme

DNA replication proceeds simultaneously at several sites on the same molecule. What separates the base pair at the start of DNA replication

Same---Different

Different molecules can diffuse at the ___ times and in ____ directions.

Moving

Diffusion "works" because molecules are always _____.

Ends

Diffusion ___ when molecules are evenly spread out.

Evenly spread out

Diffusion ends when molecules are ____.

Embryonic stem cells derive from human embryos, which are destroyed to obtain the cells. The destruction of human embryos is an ethical problem. And, the DNA in an embryonic stem cell would differ from the DNA of the person being treated, which could result in immune problems or rejected of tissue.

Discuss two reasons why the therapeutic use of embryonic stem cells can present a problem.

Moving

Even when diffusion ends the molecules are still ____.

Transcription factors bind to DNA and either promote or inhibit the transcription of a gene. If they promote the transcription of a particular gene, then that gene will be transcribed and the mRNA subsequently translated into protein. If gene transcription is inhibited, then there will be no way of synthesizing the gene's corresponding protein.

Explain how a transcription factor ultimately determines whether or not a protein will be present in a given cell?

DNA replication is said to be semiconservative because, after replication is complete, one of the two parent DNA strands makes up half of each new DNA molecule. The other half is a newly synthesized strand. Therefore, half ("semi") of each daughter DNA molecule is from the parent molecule and half is a new molecule.

Explain in your own words why DNA replication is said to be "semiconservative"?

The structure of the Golgi apparatus is suited to its function because it is a series of flattened membranous discs; substances are modified and packaged in sequential steps as they travel from one disc to the next. The structure of Golgi apparatus also involves a receiving face and a sending face, which organize cellular products as they enter and leave the Golgi apparatus. The ER and the mitochondria both have structural specializations that increase their surface area. In the mitochondria, the inner membrane is extensively folded, which increases surface area for ATP production. Likewise, the ER is elaborately wound throughout the cell, increasing its surface area for functions like lipid synthesis, Ca++ storage, and protein synthesis

Explain why the structure of the ER, mitochondria, and Golgi apparatus assist their respective functions

Enter---Leave

For a cell to survive, materials (food, O2) must ___ a cell while wastes must ____ the cell.

Higher temperatures speed up diffusion because molecules have more kinetic energy at higher temperatures.

How does temperature affect diffusion rate, and why?

3

How many "letters" of an RNA molecule, in sequence, does it take to provide the code for a single amino acid? a.1 b.2 c.3 d.4

c.active transport

Ion pumps and phagocytosis are both examples of ________. a.endocytosis b.passive transport c.active transport d.facilitated diffusion

the spindle

Mitosis results in two identical diploid cells. What structures form during prophase?

diffusion

Molecules and energy move (spread) from areas of high concentration to areas of low concentration

transport protein

Molecules stuck in the cell membrane that help move molecules against the concentration gradient.

endocytosis

Movement of a large molecule into the cell

exocytosis

Movement of a large molecule out of the cell

Diffusion

Movement of molecules from a concentrated to a less concentrated area.

Absolute Zero

Only time when molecules do not move.

concentration gradient

Particles moving in a solution from an area with a higher number of particles to an area with a lower number of particles

a.DNA, nucleosome, chromatin, chromosome

Place the following structures in order from least to most complex organization: chromatin, nucleosome, DNA, chromosome a.DNA, nucleosome, chromatin, chromosome b.nucleosome, DNA, chromosome, chromatin c.DNA, chromatin, nucleosome, chromosome d.nucleosome, chromatin, DNA, chromosome

Slowly, quickly, or not at all

The cell membrane allows molecules to move through ____

Permeable

The cell membrane is ____ to O2, H2O, CO2, wastes, and digested food (glucose, aa, fatty acids.)

Impermeable

The cell membrane is _____ to red blood cells, cell organelles, and large food molecules (sugars, starches, proteins, fats.)

Traffic Controller

The cell membrane is like a ___ because it can selectively decide what molecules move through.

d.down; concentration

The diffusion of substances within a solution tends to move those substances ________ their ________ gradient. a.up; electrical b.up; electrochemical c.down; pressure d.down; concentration

passive transport

The movement of molecules across a cell membranes (high concentration to low concentration) does not need energy.

active transport

The movement of molecules across a cell membranes (low concentration to high concentration) requires energy.

b.a double cell membrane

The nucleus and mitochondria share which of the following features? a.protein-lined membrane pores b.a double cell membrane c.the synthesis of ribosomes d.the production of cellular energy

They separate and move and are free to join translation of other segments of mRNA.

The ribosome binds to the mRNA molecule to start translation of its code into a protein. What happens to the small and large ribosomal subunits at the end of translation?

b.ribosomes

The rough ER has its name due to what associated structures? a.Golgi apparatus b.ribosomes c.lysosomes d.proteins

Pores

Tiny openings in the cell membrane.

Water

To diffuse through a cell membrane a material must be dissolved in ____.

a.nucleus; cytoplasm

Transcription and translation take place in the ________ and ________, respectively. a.nucleus; cytoplasm b.nucleolus; nucleus c.nucleolus; cytoplasm d.cytoplasm; nucleus

A cyclin is one of the primary classes of cell cycle control molecules, while a cyclin-dependent kinase (is one of a group of molecules that work together with cyclins to determine progression past cell checkpoints. By interacting with many additional molecules, these triggers push the cell cycle forward unless prevented from doing so by "stop" signals, if for some reason the cell is not ready.

What are cyclins and cyclin-dependent kinases, and how do they interact?

These four phenomena are similar in the sense that they describe the movement of substances down a particular type of gradient. Osmosis and diffusion involve the movement of water and other substances down their concentration gradients, respectively. Filtration describes the movement of particles down a pressure gradient, and the movement of ions away from like charge describes their movement down their electrical gradient.

What do osmosis, diffusion, filtration, and the movement of ions away from like charge all have in common? In what way do they differ?

b.stop certain cells from dividing

What is a primary function of tumor suppressor genes? a.stop all cells from dividing b.stop certain cells from dividing c.help oncogenes produce oncoproteins d.allow the cell to skip certain phases of the cell cycle

Processing, packaging, and moving materials manufactured by the cell.

What is the primary role of the endomembrane system?

Only materials that are relatively small and nonpolar can easily diffuse through the lipid bilayer. Large particles cannot fit in between the individual phospholipids that are packed together, and polar molecules are repelled by the hydrophobic/nonpolar lipids that line the inside of the bilayer.

What materials can easily diffuse through the lipid bilayer, and why?

c.cells from the umbilical cord and from baby teeth

What multipotent stem cells from children sometimes banked by parents? a.fetal stem cells b.embryonic stem cells c.cells from the umbilical cord and from baby teeth d.hematopoietic stem cells from red and white blood cells

One or both of the new daughter cells would accidently receive duplicate chromosomes and/or would be missing certain chromosomes.

What would happen if anaphase proceeded even though the sister chromatids were not properly attached to their respective microtubules and lined up at the metaphase plate?

High and Low

When working a diffusion problem, you must 1st identify the ___ concentrations.

c.They are all polymers of protein subunits.

Which of the following is a feature common to all three components of the cytoskeleton? a.They all serve to scaffold the organelles within the cell. b.They are all characterized by roughly the same diameter. c.They are all polymers of protein subunits. d.They all help the cell resist compression and tension.

a.production of proteins

Which of the following is a function of the rough ER? a.production of proteins b.detoxification of certain substances c.synthesis of steroid hormones d.regulation of intracellular calcium concentration

c.DNA contains alternating sugar-phosphate molecules whereas RNA does not contain sugars

Which of the following is not a difference between DNA and RNA? a.DNA contains thymine whereas RNA contains uracil b.DNA contains deoxyribose and RNA contains ribose c.DNA contains alternating sugar-phosphate molecules whereas RNA does not contain sugars d.RNA is single stranded and DNA is double stranded

d.the intron

Which of the following is not made out of RNA? a.the carriers that shuffle amino acids to a growing polypeptide strand b.the ribosome c.the messenger molecule that provides the code for protein synthesis d.the intron

b.attaching complementary nucleotides to the template strand

Which of the following is part of the elongation step of DNA synthesis? a.pulling apart the two DNA strands b.attaching complementary nucleotides to the template strand c.untwisting the DNA helix d.none of the above

a.mitochondria

Which of the following organelles produces large quantities of ATP when both glucose and oxygen are available to the cell? a.mitochondria b.peroxisomes c.lysosomes d.ER

g1

Which of the following phases is characterized by preparation for DNA synthesis? a.G0 b.G1 c.G2 d.S

c.CGAATATA

Which of the following sequences on a DNA molecule would be complementary to GCTTATAT? a.TAGGCGCG b.ATCCGCGC c.CGAATATA d.TGCCTCTC

c.ribosomes

Which of the following structures could be found within the nucleolus? a.chromatin b.histones c.ribosomes d.nucleosomes

c.hematopoietic

Which type of stem cell gives rise to red and white blood cells? a.endothelial b.epithelial c.hematopoietic d.mesenchymal

During cell division, one cell divides to produce two new cells. In order for all of the cells in your body to maintain a full genome, each cell must replicate its DNA before it divides so that a full genome can be allotted to each of its offspring cells. If DNA replication did not take place fully, or at all, the offspring cells would be missing some or all of the genome. This could be disastrous if a cell was missing genes necessary for its function and health.

Why is it important that DNA replication take place before cell division? What would happen if cell division of a body cell took place without DNA replication, or when DNA replication was incomplete?

Receptor-mediated endocytosis is more selective because the substances that are brought into the cell are the specific ligands that could bind to the receptors being endocytosed. Phagocytosis or pinocytosis, on the other hand, have no such receptor-ligand specificity, and bring in whatever materials happen to be close to the membrane when it is enveloped.

Why is receptor-mediated endocytosis said to be more selective than phagocytosis or pinocytosis?

solution

a mixture of solute and solvent

aqueous solutions

a solution in which the solvent is water. (sugar dissolved in water is an aqueous solution)

hypertonic

a solution that contains a higher concentration of solutes (remember when someone is hyper, they seem to have MORE energy).

hypotonic

a solution that contains a lower concentration of solutes (remember hypo rhymes with low)

isotonic

a solution that contains an equal concentration of solute and solvent

cell shrinks if too much water exits.

crenation

assisted transport by protein

facilitated diffusion

store dna

functions of a nucleus

assemble ribosomes

functions of nucleous

1.physical barrier 2. selective permeability 3. electrochemical gradient 4. comm

functions of plasma membrane

75 trillion cells in human body

how many cells inhuman body

exerted by fluid on the inside wall of its container.

hydrostatic pressure

embedded within & extend across PM. Many are glycoproteins

integral protein

rupture of cell if too much water enters the cell.

lysis

H2O movement in/out of cell causes changes in cell volume/pressure

osmosis & tonocity

Pressure exerted by moving H2O across semipermeable membrane due to diff. in solute concentrations

osmotic pressure

attached ("anchored") loosely to external/internal PM.

peripheral

cytology

study of cells

concentration

the amount of particles in an area

osmosis

the diffusion of water

solvent

the liquid that is doing the dissolving (usually a liquid, but can sometimes be a solid or gas)

solute

the substance that is being dissolved (salt/sugar)