Biology 181 Quiz 2

Protein that spans the phospholipid bilayer one or more times is?

A transmembrane protein.

Are part of a prokaryotic cell except?

An endoplasmic reticulum.

Water passes quickly through cell membranes because:

It moves through aquaporins in the membrane.

Protein to be an integral membrane protein it would have to be?

Amphipathic, with at least one hydrophobic region.

Prokaryotes are classified as belonging to two different domains. What are the domains?

Bacteria and archaea.

Move through the lipid bilayer of a plasma membrane most rapidly?

CO2.

Thylakoids, DNA, and ribosomes are all components found in?

Chloroplasts.

Bacteria and archaea cells is correct?

DNA is present in both archaea cells and bacteria cells.

Ions diffuse across membranes through specific ion channels?

Down their electrochemical gradients.

Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through:

Gap junctions.

Produces and modifies polysaccharides that will be secrete?

Golgi apparatus.

Plant cell, DNA may be found?

In the nucleus, mitochondria, and chloroplasts.

Feature of a carrier protein in a plasma membrane?

It exhibits a specificity for a particular type of molecule.

Which is correct about diffusion?

It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

Avantage of light microscopy over electron microscopy is that?

Light microscopy allows one to view dynamic processes in living cells.

Contains hydrolytic enzymes?

Lysosome.

Bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in?

Lysosomes.

Voltage across a membrane called?

Membrane potential.

Movement of vesicles within the cell depends on what cellular structures?

Microtubules and motor proteins.

ATP synthesis in eukaryotic cells?

Mitochondrion.

Plant cell organelle contains its own DNA and ribosomes?

Mitochondrion.

Cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from?

Nearly any eukaryotic organism.

Receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis?

On the inside surface of the vesicle.

Are not embedded in the hydrophobic portion of the lipid bilayer at all?

Peripheral proteins.

Animal cell organelle contains enzymes that transfer hydrogen from various substrates to oxygen?

Peroxisome.

White blood cells engulf bacteria through what process?

Phagocytosis.

Major structural components of the cell membrane?

Phospholipids and proteins.

Difference between pinocytosis and receptor-mediated endocytosis is that?

Pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity.

Cell with a predominance of free ribosomes is most likely?

Producing primarily cytoplasmic proteins.

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

Proteins.

Proton pumps are used in various ways by members of every domain of organisms: bacteria, archaea, and eukarya. According to evolution theory, what does this most probably mean?

Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.

synthesis of proteins that may be exported from the cell?

Rough ER.

Primary objective of cell fractionation is to?

Separate the major organelles so that their particular functions can be determined.

Molecules pass through a cell membrane most easily?

Small and hydrophobic.

Lliver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?

Smooth ER.

Synthesis of oils, phospholipids, and steroids?

Smooth endoplasmic reticulum.

Unsaturated fatty acids help keep any membrane more fluid at lower temperatures?

The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.

Cause of the size limits for certain types of cells?

The need for a surface area of sufficient area to support the cell's metabolic needs

Fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?

They can move laterally along the plane of the membrane.

Function of polysaccharides attached to the glycoproteins and glycolipids of animal cell membranes is?

To mediate cell-to-cell recognition.