Exam 2

Question 1

What can you see with a light microscope? With an electron microscope?

Answer 1

With a light microscope can see most plant and animal cells along with large organelles and bacteria, an electron microscope can be used to see a small organelle, like a ribosome.

Question 2

What are 3 similarities and 3 differences between prokaryotes and eukaryotes?

Answer 2

Prokaryotes have Nucleoid, circular DNA, Binary Fission replication, Cell wall and Fimbriae, Eukaryotes have Nucleus, membrane-bound organelles, Cytoskeleton, and Mitotic replication of linear double helix DNA.

Question 3

Function/characteristics of nucleus

Answer 3

Contains genetic material in form of chromosomes and chromatin; surrounded by envelope

Question 4

Plasma Membrane

Answer 4

Selective barrier; allows passage of
nutrients and waste in/out of cell

Question 5

Nucleolus

Answer 5

Specialized structure in the nucleus

Question 6

Rough ER

Answer 6

Site of protein synthesis; has ribosomes on outer surface

Question 7

Ribosomes

Answer 7

Helps assemble proteins

Question 8

Smooth ER

Answer 8

Detoxifies ingested drugs and poisons; synthesis of lipids; carbohydrate metabolism; stores calcium

Question 9

Golgi Apparatus

Answer 9

Sorting, packaging and shipping center

Question 10

Lysosomes

Answer 10

Membranous sac of enzymes used to
digest macromolecules (phagocytosis)

Question 11

Vacuoles

Answer 11

Usually derived from ER or Golgi;
selective transport and cell waste

Question 12

Mitochondria

Answer 12

Powerhouse organelle that supplies
eukaryotes with energy via cellular respiration

Question 13

Chloroplasts

Answer 13

Additional energy source for plants using photosynthesis

Question 14

Peroxisomes

Answer 14

Has specialized metabolic functions; produces hydrogen peroxide as a by-product and then converts it to water

Question 15

Which organelles are part of the endomembrane system?

Answer 15

plasma membrane, nuclear envelope, ER, Golgi, lysosomes, vesicles and vacuoles

Question 16

What is the endomembrane system?

Answer 16

Endomembrane System is an interconnected cellular network

Question 17

What are the three types of cell junctions found in animal cells?

Answer 17

Tight Junction, Desmosomes, Gap Junctions

Question 18

Tight Junction

Answer 18

secure barrier of proteins between adjacent plasma membranes that prevents leakage of extracellular fluid of skin cells (“quilted”)

Question 19

Desmosomes

Answer 19

anchor junction that fastens cells together in strongs sheets (muscle-to-muscle)

Question 20

Gap Junctions

Answer 20

communicating junctions; protein port that acts as a channel between cell membrane; allows direct cell transfer of small ions and nutrients to pass between cells

Question 21

Fluid mosaic model

Answer 21

model of cell membrane structure; phospholipid bilayer with drifting protein molecule throughout; selectively permeable

Question 22

Semi permeable

Answer 22

regulates passage of substances across the membrane

Question 23

What parts of the plasma membrane are hydrophilic? What parts are hydrophobic?

Answer 23

Hydrophilic head, hydrophobic tails.

Question 24

Be able to explain each in detail. What are the six major functions of membrane
proteins?

Answer 24

1. Transport - provide channel to shuttle substances from one side of membrane to other
2. Enzymatic Activity - serves as active site where target molecules bind
3. Signal Transduction -a signal molecule causes that receptor protein to change shape, relaying a message to the inside of cell, usually by binding to a cytoplasmic protein
4. Cell-cell Recognition - proteins serves as temporary identification tags
5. Intercellular Joining - intercellular adhesion to various kinds of junctions, long lasting
6. ECM & Cytoskeleton Attachment -stabilize shape of cell and contents via microfilaments; coordinate inter and extracellular exchanges

Question 25

What molecule is involved in cell-cell recognition? What is the difference between a glycolipid and a glycoprotein?

Answer 25

Glycoprotein or glycolipids Glycolipids is where carb attaches to lipid, whereas glycoprotein is where carb attaches to protein

Question 26

What are the three ways cells signal to each other?

Answer 26

Gap junctions, desmosomes, tight junctions

Question 27

What are two similarities between GPCRs and ligand-gated ion channels? How are they different?

Answer 27

Similarities = both transmembrane receptors and they both require energy Differences = GCPRs utilize the second messenger cAMP, ligand-gated ion channels are important in synapsis/nervous system

Question 28

What are the three stages of cell signaling? Which occurs outside the cell? Which occurs inside the cell? What is the signal molecule called?

Answer 28

Reception, Transduction, and Response Reception occurs outside the cell, while transduction and response occur inside the cell Signal molecule is called Ligand (first messenger)

Question 29

What are the three types of transport proteins? Which is responsible for moving water?

Answer 29

Channel proteins, carrier proteins, gated channel proteins. Channel proteins are responsible for moving water

Question 30

How are carrier and channel proteins similar? How are they different?

Answer 30

Both use passive transport. Channel Proteins - protein tunnels through bilayer like a tunnel Carrier Proteins - alternates between 2 different shapes like a see-saw

Question 31

What is diffusion? Does it require energy?

Answer 31

Diffusion is the net movement of particles (solvent and solute) generally from a region of higher concentration to a region of lower concentration; driven by a gradient; takes place in any medium. It does not require energy.

Question 32

In terms of concentration gradient, how do molecules diffuse? What is equilibrium (dynamic)?

Answer 32

from a region of higher concentration to a region of lower concentration. Equilibrium is like that seesaw shit

Question 33

What is osmosis?

Answer 33

Osmosis is the diffusion of water when a membrane is not permeable to a solute

Question 34

hypertonic vs hypotonic

Answer 34

If the solution is hypertonic it will shrink, if its isotonic it will stay the same, if its hypotonic it will swell or burst

Question 35

What is facilitated diffusion, and how is it different from simple diffusion?

Answer 35

Facilitated Diffusion - passage of molecules and ions down their electrochemical gradient (no energy required) across a membrane with the assistance of specific transmembrane transport proteins. It’s different from simple diffusion because F D involves the assistance of specific transmembrane transport proteins.

Question 36

Which major molecule is used in facilitated diffusion? Does it require energy?

Answer 36

specific transmembrane transport proteins, it does not require energy

Question 37

What is active transport? What molecule is involved in Active Transport that is not used in diffusion?

Answer 37

the movement of a substance across a cell membrane against its concentration gradient, mediated by specific transport proteins; requires energy. ATP is used.

Question 38

What two molecules are involved in the sodium potassium pump?

Answer 38

Sodium (Na+) and potassium (k).

Question 39

What is the major difference between passive transport and active transport?

Answer 39

Active transport requires ATP.

Question 40

What is secondary active transport? Be able to explain in terms of gradients

Answer 40

Secondary active transport is transport of molecules across the cell membrane utilizing energy in other forms than ATP. This energy comes from the electrochemical gradient created by pumping ions out of the cell (ex: Na+K pump).

Question 41

What are the three types of bulk transport? Which moves molecules into the cell? Which moves molecules out of the cell? Do they require energy?

Answer 41

Phagocytosis, pinocytosis, exocytosis. Endocytosis moves molecules into the cell. Exocytosis moves molecules out of the cell. All require energy.

Question 42

Describe the 2 Types of Transduction Cascades

Answer 42

Protein Phosphorylation: a sequence of signaling pathway events where one enzyme phosphorylates another, causing a chain reaction leading to the phosphorylation of thousands of proteins Second Messenger: small non-protein water-soluble molecules and ions that relay signals received by cell-surface receptors to effector (response) proteins

Question 43

How do prokaryotes and eukaryotes make up for their small size with surface area?

Answer 43

Cilia