PHYS 3315 EXAM 1 practice

When a blood vessel is injured, platelets release clotting factors that attract more platelets to the site, forming a clot to prevent further blood loss.

True or False: This is an example of homeostatic regulation by a negative feedback loop.

False - positive feedback

A lizard shuttling between the sun and shade to maintain a stable body temperature is best described as a ________.

behaviorally thermoregulating ectotherm

Fish that live in colder water are likely to have ________ fatty acid chains in their membrane compared to fish in warm environments.

more unsaturated

Phospholipids in the cell membrane are composed of:

hydrophilic head & hydrophobic tail

When DNA methylation occurs in a promoter region, it typically:

blocks gene trancription

Which of the following is FALSE about intracellular receptors?

• They are bound to the cell membrane

• They act as transcription factors when bound with their ligand

• They are proteins

they are bound to the cell membrane

True or false: your transcriptome can change within a few hours.

True

As temperature increases, diffusion rate ___________

and as distance between solutions increases, diffusion rate ____________.

increases, decreases

Which of these best describes facilitated diffusion?

 

• Passive movement in the direction of the concentration gradient

• Uses a transporter to cross in the direction of the concentration gradient

• Uses a transporter to cross in the direction opposite to concentration gradient

uses a transporter to cross in the direction of the concentration gradient

Hot temperatures can alter protein conformation in a process called __________. However, ________ can assist in conformational folding thereby returning the protein's function.

denaturation, chaperones

The way that your thermostat on your home controls the temperature can be described as _______.

negative feedback

Which of the following is true:

• a proteins 3D structure is fixed and unchangeable

• there are only 2 possible 3D structures a protein can take

• a protein’s primary structure is held by strong, covalent bonds

• there are only 22 possible sequence of amino acids that can for a protein

a protein’s primary structure is held together by strong, covalent bonds

what is an effect of cholesterol embedded in the membrane:

• It stabilizes the membrane at high temperatures by raising the melting point

• It preserves fluidity of the membrane at low temperatures by preventing phospholipids from packing too tightly

• Both of the above are true

• Neither of the above are true

both are true

You observe epithelial cells with a “brush border” under the microscope. What assumption can you make about these cells?

the cells are likely involved in absorption and secretion

Which of the following best describes the role of ATP in cellular processes?

• ATP acts as a secondary messenger in signal transduction pathways

• ATP stores and transfers energy for cellular processes

• ATP is a substrate for DNA replication

• ATP provides structural support to cell membranes

ATP stores and transfers energy for cellular processes

Glycolysis, as a method of ATP production, is characterized by which of the following?

• It requires oxygen to proceed and occurs in the mitochondria

• It does not require oxygen and results in the formation of pyruvate or lactic acid

• It produces a high yield of ATP per glucose molecule

• It is the primary method of energy production in aerobic organisms

it doesn’t require oxygen and results in the formation of pyruvate or lactic acid

Which statement about brown adipose tissue (BAT) is FALSE?

• BAT cells contain more mitochondria than typical adipose cells

• BAT is critical in non-shivering thermogenesis

• BAT is often observed in adult humans living in cold climates

• BAT is often observed in hibernating mammals

BAT is often observed in adult humans living in cold climates

DNA methylation typically occurs on which nucleotide base?

C - cytosine

Which of these regulatory regions for a given gene is closer to the transcription start site? promoter, enhancer, or exon

promoter