exam 1

Phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

The main difference between active and passive transport across a cell membrane is

Active transport requires energy while passive transport does not Active transport involves the movement of molecules against their concentration gradient

You would more likely find a phospholipid in...

Alaskan salmon's skin cell

The atomic number of hydrogen is 1, and its mass is 1.00784 amu. How many neutrons does elemental hydrogen (H) contain?

0

You would expect he cells found in the liver of an elephant to be about 100 times larger than the cells found in your own liver.

False

In eukaryotes, endocytosed solid particles are broken into smaller subunits by

Lysosomes

The hydrolysis of macromolecules and organelles that are no longer needed in the cells is most likely to take place in which of the following?

Lysosomes

In plant cells, most of the ATP to be used by the cell is produced by which of the following?

Mitochondria

Which of the following polysaccharides are you most likely to find in the exoskeleton of a locust (grasshopper)?

chitin

A Gram positive bacterium would...

Have a cell wall made of peptidoglycan

Which of the following is/are a monosaccharide?

fructose

The average intracellular voltage of most cells varies between which two values?

-5 to -100 millivolts

Tomato juice has a pH around 4.0, and distilled water has a pH around 7.0. This means that tomato juice is

1000 times as acidic as distilled water

The plasma membrane is best described as:

A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins, and carbohydrates

Which of the following structures would least likely be found in a bacterium?

A lysosome

The carboxyl group of an amino acid placed in a very acidic environment (pH=2.0) would look like which of the following choices?

B. Normal Carboxyl Group

Urea is one of the first (if not THE first) organic compound to be synthetized in a dish. Our cells produce urea to get rid of nitrogenous wastes. Based on your knowledge of macromolecules, you would expect nitrogenous wastes to come from the metabolism of

Both proteins and nucleic acids

The hypothetical cell represented below has a plasma membrane made of phospholipids in which are embedded a few leak channels only - nothing else. When the cell is immersed in the following environment, some molecules are able to cross the cell membrane while others are not. Which of the following answers best describes the net movement of calcium, as this system changes toward equilibrium?

Calcium would move out of cell

Geometric Isomers

Compounds that have the same molecular formula but differ in the spatial arrangements of their atoms.

The bonds that hold hydrogen and oxygen within a water molecule are called

Covalent Bonds

During the "firing" of a neuron, sodium moves along (down) its concentration gradient, from the extracellular environment into the cell. This is an example of

Facilitated diffusion

An uncharged species of nitrogen that has a mass of 15 AMUs (or daltons) would be called a nitrogen ion

False

Which of the following structures allows cells to "read" the extracellular matrix and be influenced by it?

Integrin proteins

Which of the following is true regarding your mitochondrial DNA?

It is almost identical to your mother's mitochondrial DNA It is virtually identical in all the cells of your body

Which of the following is accurate regarding lactose?

Lactose is composed of galactose and glucose

Proportionally to its volume, a basketball has _____ surface area than a marble.

Less

The hypothetical cell represented below has a plasma membrane made of phospholipids in which are embedded a few leak channels only - nothing else. When the cell is immersed in the following environment, some molecules are able to cross the cell membrane while others are not. Which of the following answers best describes the net movement of oxygen, as this system changes toward equilibrium?

Oxygen would move out of the cell

Which of the following factors contribute significantly to increasing cell membrane fluidity at room temperature?

Presence of double bonds in the fatty acyl chains

The hypothetical cell represented below has a plasma membrane made of phospholipids in which are embedded a few leak channels only - nothing else. When the cell is immersed in the following environment, some molecules are able to cross the cell membrane while others are not. Which of the following answers best describes the net movement of small hydrophobic molecules (SHM), as this system changes toward equilibrium?

Small hydrophobic molecules would move into the cell

The hypothetical cell represented below has a plasma membrane made of phospholipids in which are embedded a few leak channels only - nothing else. When the cell is immersed in the following environment, some molecules are able to cross the cell membrane while others are not. Which of the following answers best describes the net movement of chloride, as this system changes toward equilibrium?

There wouldn't be any net movement of chloride

DNA and RNA nucleotides have a sugar component

True

The liver is heavily involved in detoxifying the blood. Based on this statement, which of the following characteristic would you expect to best describe liver cells (= hepatocytes)?

Very large smooth endoplasmic reticulum

The hypothetical cell represented below has a plasma membrane made of phospholipids in which are embedded a few leak channels only - nothing else. When the cell is immersed in the following environment, some molecules are able to cross the cell membrane while others are not. Which of the following answers best describes the net movement of water, as this system changes toward equilibrium?

Water would move into the cell

Which of the following statement(s) is/are correct about ATP?

a. ATP serves as an energy "currency" inside the cell b. The reaction of ATP to ADP + P is coupled to endergonic reactions c. The reaction of ATP to ADP + P is an exergonic reaction d. The main source of ATP production for an entire cell is its mitochondria

How many covalent bonds can a carbon atom form?

four

The small intercellular connections made of the protein connexin that allow the passage of small molecules such as Ca++ and ATP between adjacent animal cells are known as...

gap junctions

Proteins are broken down into individual amino acids during a process known as

hydrolysis

Match the level of protein structure on the left with the appropriate description on the right. i. Primary w. 3-dimensional shape of polypeptide chain ii. Secondary x. linear sequence of amino acids iii. Tertiary y. assembly of subunits into functional protein iv. Quaternary z. hydrogen bonding within peptide backbone (ex: α-helix)

i=x, ii=z, iii=w, iv=y

Water has its highest density when it is in its

liquid state

Which of the following molecules most closely resembles ATP?

nucleotide