The Cellular Level of Organization

Question 1

what are the 3 parts that a cells is divided into?

Answer 1

Plasma cells membrane
cytoplasm
nucleus

Question 2

What is glycocalyx

Answer 2

is the sugary coat on the extracellular surface of the plasma membrane. it is composed of the carb portions pf membrane glycolipids and glycoproteins

Question 3

when stimulating a cell, the hormone insulin first binds ti a protein in the plasma membrane. this action best represents which membrane protein function?

Answer 3

the membrane protein that binds to insulin acts as a receptor.

Question 4

how would having a fever affect body processes that involve diffusion?

Answer 4

because fever involves an increase in body temp, the rates of all diffusion processes would increase

Question 5

what types of molecules move across the lipid bilayer of the plasma membrane via simple diffusion?

Answer 5

nonpolar hydrophobic molecules (O2, CO2, N, fatty acids, steroids ad fat soluble vitamins) plus small uncharged polar molecules (Water, urea and small alcohols) move across the lipid bilayer of the plasma membrane through process of simple diffusion.

Question 6

is the concentration of K+ in the body cells higher in the cytosol or in extracellular fluid?

Answer 6

higher in cytosol

Question 7

does insulin alter glucose transport by facilitated diffusion?

Answer 7

yes. insulin promotes insertion of glucose transporter (GluT) in the plasma membrane which increases the cellular glucose uptake by carrier-mediated facilitated diffusion

Question 8

will the fluid level in the right arm rise until the water concentrations are the same in both arms?

Answer 8

no. the water concentrations can never be the same in both arms because the left arm contains pure water and the right arm contains a solution that is less that 100% water

Question 9

will a 2% solution of NaCl cause hemolysis or crenation of RBCs

Answer 9

crenation

Question 10

what is the role of ATP in the operation of this pump?

Answer 10

ATP adds a phosphate group to the pump protein, which changes the pumps 3D shape, ATP transfers energy to power the pump

Question 11

what is the main difference between primary and secondary active transport mechanisms?

Answer 11

in secondary active transport, hydrolysis of ATP is used indirectly to drive the activity of symporter or antiporter proteins, this reaction directly powers the pump protein in primary active transport

Question 12

What are several other examples of ligands that can undergo receipt-mediated endocytosis?

Answer 12

transferrin, vitamins and hormones

Question 13

what triggers pseudopod formation?

Answer 13

the binding of particles to a plasma membrane

Question 14

how do receptor-mediated endocytosis and phagocytosis differ from bulk-phase endocytosis

Answer 14

receptor-mediated endocytosis and phagocytosis involve reception proteins, bulk-phase endocytosis doesnt

Question 15

which cytoskeletal component helps form the structure of centrioles, ilia, and flagella?

Answer 15

microtubules

Question 16

if you observe that a cell did not have a centrosome, what could you predict about its capacity for cell division?

Answer 16

would not be able to undergo cell division

Question 17

what is the difference between cilia and flagella?

Answer 17

cilia moves fluid across cell surfaces, flagella moves the entire cell

Question 18

where are the subunits of ribosomes synthesized and assembled?

Answer 18

large and small subunits are synthesized in the nucleolus within the nucleus, then assembled in the cytoplasm

Question 19

what are the structural and functional differences between rough and smooth ER?

Answer 19

Rough has attached ribosomes, Smooth doesn’t, Rough synthesizes proteins that will be exported from the cell, Smooth is associated with lipid synthesis and other reactions

Question 20

how do the entry and exit faces differ in function (Golgi complex)

Answer 20

entry receives and modifies proteins from rough ER
exit modifies, sorts and packages molecules for transport to other destinations

Question 21

what are the 3 general destinations for proteins that leave the Golgi complex?

Answer 21

some proteins are secreted from the cell by exocytosis some are incorporated into the plasma membrane and some occupy storage vesicles that become lysosomes

Question 22

what is the name of the process by which worn-out organelles are digested by lysosomes?

Answer 22

autophagy

Question 23

how do the mitochondrial crustal contribute to its ATP - producing function?

Answer 23

increase the surface area available for chemical reactions and contain some enzymes needed for ATP production

Question 24

what is chromatin?

Answer 24

a complex of DNA, proteins and some RNA

Question 25

what are the components of nucleosomes?

Answer 25

a nucleosome is a double-stranded molecule of DNA wrapped twice around a core of eight histones

Question 26

why are proteins important in the life of a cell?

Answer 26

proteins determine the physical and chemical characteristics

Question 27

what roles do the P and A sites serve for mRNA

Answer 27

the P holds the tRNA attached to the growing polypeptide, the A holds the tRNA carrying the next amino acid to be added to the growing polypeptide

Question 28

what is the function of a stop codon?

Answer 28

when a ribosome encounters a stop codon at the A site it releases the completed protein from the final tRNA

Question 29

during which phase of the cells cycle does DNA replication occur?

Answer 29

S phase of interphase

Question 30

why must DNA replication occur before cytokinesis ion somatic cell division?

Answer 30

so that each of the new cells will have a complete genome

Question 31

when does ctyokinesis begin?

Answer 31

late anaphase

Question 32

how does crossing-over affect the genetic count of the haploid gametes?

Answer 32

the result of crossing-over is that 4 haploid gametes are genetically unlike each other and gentetically unlike the starting cell that produced them

Question 33

how does anaphase I of meiosis differ from anaphase of mitosis?

Answer 33

Anaphase I - the pair chromatids are held together by a centromere and don’t separate
Anaphase of Mitosis - the paired chromatids separate and the centromeres split

Question 34

why are sperm the only body cells that have a flagellum?