Bio Exam 2 Specific

Question 1

Differences between Eukaryotes and Prokaryotes

Answer 1

Eukaryotes:
- larger
- DNA in nucleus
- organelles

Prokaryotes:
- smaller
- no organelles

Question 2

Similarities between Eukaryotes and Prokaryotes

Answer 2

Cytoplasm
Plasma Membrane

Question 3

Endomembrane System

Answer 3

Nuclear Envelope (double layrered)
Endoplasmic Reticulum (Rough and Smooth)
Golgi Apparatus
Vesicles (pouches of plasma membrane)

Question 4

Chromatin v Chromsome

Answer 4

Chromatin: loosely wound DNA
Chromosome: tightly wound

Question 5

Job of nucleus

Answer 5

house and copy DNA

Question 6

3 types of cytoskeleton

Answer 6

Microtubules
Intermediate Filaments
Microfilaments

Question 7

Microtubules

Answer 7

made of Tubullin
- hollow
- movement and support (tracks for motor proteins)
- can originate from centrosome
- cilia and flagella, separation of DNA
- arranged in cricles of 9 triplets or doublets

Question 8

Intermediate Filaments

Answer 8

made of Keratin
- twisted fibrous proteins
- many originate from centrosome, built from centrioles
- anchor and structure

Question 9

Microfilaments

Answer 9

made of Actin protein
- muscle contractions
- cytoplasmic streaming
- cell shape

Question 10

Cisternea

Answer 10

flattened membrane vesicles found in the ER

Question 11

Plasmodesmata

Answer 11

cytosol, water, ions

Question 12

4 types of junctions

Answer 12

1) Tight junctions: no leaks
2) Desmosome: velcro (strong–> high mechanical stress)
3) Gap junction: channel (quick movement from one cell to another–> rapid signaling)
4) Plasmodesmata: plant cell wall channels

Question 13

6 fucntions of membrane proteins

Answer 13

transport channels
receptors fro signaling molecules
cytoskeleton
enzymatic activity
intercellular attachment
cell - cell recognition

Question 14

Amphipathic

Answer 14

partially hydrophobic, partially hydrophilic

Question 15

cholestorol

Answer 15

reduces membrane fluidity but at low temps stops it from freezing solid

Question 16

Active Transport

Answer 16

REQUIRES ENEGY!
- primary
- secondary (cotransport)
- vesicular

Question 17

Vesicular Transport

Answer 17

Exocytosis (exit the cell)

Endocytosis (into the cell)
- receptor mediated
-pinocytosis (cell drinking)
- Phagocytosis (cell eating)

Question 18

Passive Transport

Answer 18

NO ENERGY NEEDED!

Diffusion
- simple
- osmosis (water)
- facilitated –> aquaporins, channel mediated, carrier mediated

Question 19

Diffusion

Answer 19

substances moves until they are equally and randomly distributed

Question 20

Simple diffusion

Answer 20

solute moves from high to low

Question 21

Tonicity

Answer 21

ability of a solution to alter cells water volume

Question 22

Active Transport

Answer 22

moves molecules against their concentration gradient

Question 23

Co-transport

Answer 23

uses stored energy from active transport
building a concentration gradient in order to do other work

Question 24

Vesicular (bulk) Transport

Answer 24

molecules moved in tiny containers called vesicles
endocytosis (inside the cell)
exocytosis (outside the cell)

Question 25

electrogenic pump

Answer 25

voltage differences on either side of the cell membrane, ex. 3Na + and 2K +

Question 26

Local signalling

Answer 26

• gap junctions
• cell - cell recognition
• paracrine = local regulator
• synaptic

Question 27

Long distance signaling

Answer 27

• endocrine
• nervous tissue

Question 28

3 stages of cell signaling

Answer 28

Reception
Transduction
Response

Question 29

Reception

Answer 29

recognize the signaling molecule

Question 30

Transduction

Answer 30

convert original signal into form that can trigger cellular response. often involves relay molecules

Question 31

Response

Answer 31

finally triggers specific activity

Question 32

ligand

Answer 32

signaling molecule, binds specifically to another molecule

Question 33

G protein coupled receptor

Answer 33

• utilizes transmembrane receptor
• binds GTP (energy shuttle molecule) to a G protein
• activates another enzyme

Question 34

Ligand gated ion channel

Answer 34

• channel only opens to specific ligand binds
• allows movement of molecules that may trigger intracellular response

Question 35

Intracellular Receptors

Answer 35

diffuse straight through the membrane

Question 36

Protein Kinase

Answer 36

transfer phosphate group –> phosphorylate –> activate

Question 37

Protein Phosphate

Answer 37

remove a phosphate –> deactivate

Question 38

chemical energy

Answer 38

potential energy is available in chemical reaction

Question 39

Thermal energy

Answer 39

kinetic energy associated with random movements if atoms or molecules

Question 40

Anabolic

Answer 40

or endergonic reactions: build up
positive change in G
lessens entropy locally

Question 41

Catabolic

Answer 41

or exergonic: tears down
negative change in G
spontaneous: does not require energy from outside to start reaction so can happen whenever
increases entropy

Question 42

change in G

Answer 42

final G - initial G

Question 43

Energy Coupling

Answer 43

using an exergonic reaction to drive an endergonic one

Question 44

Phosphorylation

Answer 44

transferring a phosphate group

Question 45

competition inhibition

Answer 45

active site is filled by “mimic” so normal substrate cant gain access

Question 46

non competitive inhibition

Answer 46

bind to a different part of the enzyme, causes enough of a change that active site isn’t accessible to normal substrate

Question 47

Allosteric Inhibition

Answer 47

stabilizes in inactive form

Question 48

Allosteric Regulation

Answer 48

activator molecule binds and stabilizes in active form

Question 49

Cooperativity

Answer 49

when actual binding influences further binding in other active sites