Bio Review unit 1 and 2

Question 1

nitrogen is an important
element for building …

Answer 1

proteins and nucleic acids.

Question 2

Phosphorus is important
for building…

Answer 2

nucleic acids and some lipids

Question 3

Dehydration reaction

Answer 3

bonds two monomers with the loss of H2O
● The -OH of one monomer bonds to the -H of
another monomer forming H2O, which is then
released
- glucose and fructose –> sucrose
○ A+B→AB + H2O

Question 4

Hydrolysis

Answer 4

breaks the bonds in a polymer by adding H2O
● One -H of the H2O bonds to one monomer and the
remaining -OH of the H2O attaches to the other
monomer
- sucrose-> glucose and fructose
○ AB + H2O → A+B

Question 5

Carbohydrates contain what groups

Answer 5

carbonyl and hydroxyl

Question 6

monosaccharides

Answer 6

simple sugars
● Molecular formulas with multiples of the
unit CH2O
● Most common is glucose
○ Nutrients and fuel for cells
■ Used in cellular respiration
● Can serve as building blocks for amino
acids, or as monomers for di- and
polysaccharides

Question 7

disaccharides

Answer 7

two monosaccharides joined together by
covalent bonds
● Most common is sucrose
○ Monomers of sucrose: glucose and fructose
○ Plants transfer carbohydrates from roots to
leaves in the form of sucrose

Question 8

Storage polysaccharides

Answer 8

Plants store starch (polymer of glucose monomers)
○ Allows plants to store excess glucose
● Animals store glycogen (polymer of glucose)
○ Stored in liver and muscle cells

Question 9

Structural polysaccharides

Answer 9

Cellulose: tough substance that forms plant cell walls
● Chitin: forms exoskeleton of arthropods

Question 10

Function of proteins include

Answer 10

Antibody-help protect the body from disease
○ Enzyme- carry out chemical reactions or assist
in creating new molecules
○ Messenger- transmit signals (ie hormones)
○ Structural- provide structure and support
○ Transport/storage- bind to and carry small
atoms and molecules through the body

Question 11

levels of protein structure

Answer 11

primary: linear chain of AA
secondary: Coils and folds due to hydrogen bonding within the polypeptide backbone. ᵬ pleated sheet- hydrogen bonds between polypeptide chains lying side by side. A helix as well
tertiary: 3D folding due to interactions between the side chains of the AAs
● Reinforced by hydrophobic interactions and disulfide bridges of the side chains
quaternary: two or more polypeptides

Question 12

nucleic acid function

Answer 12

Store, transmit and express hereditary information

Question 13

nucleotides 3 parts

Answer 13

1. Nitrogenous base
2. Five carbon sugar (pentose)
3. Phosphate group(s)

Question 14

Pyrimidines

Answer 14

one ring with 6 atoms
● Cytosine
● Thymine
● Uracil Only found in DNA
Only found in RNA

Question 15

Purines

Answer 15

one ring with 6 atoms bonded to one ring with 5 atoms
- adenine and guanine

Question 16

Saturated fatty acid

Answer 16

no double bonds between
carbons in the carbon chain = more hydrogen
(think: saturated with hydrogen)

Question 17

Unsaturated fatty acid

Answer 17

contains one or more double bonds

Question 18

All cells contain

Answer 18

plasma membrane, cytosol, chromosomes, ribosomes

Question 19

Prokaryote

Answer 19

• domains bacteria and archaea
• Dna is in the nucleotide region
• smaller in size than eukaryotes

Question 20

Eukaryote

Answer 20

• Protists, fungi, animals, and plants
• DNA is in the nucleus
• Contain bound organelles

Question 21

Compartmentalization

Answer 21

Membrane-bound organelles allow different parts of the cell to perform different functions at the same time

Question 22

Plants vs Animals

Answer 22

Plants—cell walls, central vacuole, chloroplasts, plasmodesmata
Animals—centrosomes, lysosomes, flagella

Question 23

Golgi complex functions

Answer 23

• Receives transport vesicles with materials from the ER
• Modifies the materials (ensures newly formed proteins are folded correctly or modified correctly)
• Sorts the materials
• Adds molecular tags
• Packages materials into new transport vesicles that exit the membrane via exocytosis

Question 24

Lysosomes functions

Answer 24

• Hydrolyzes macromolecules in animal cells
  Autophagy: lysosomes can recycle their own cell’s organic materials
• Allows the cell to renew itself

Question 25

Endosymbiont Theory:

Answer 25

The theory that explains the similarities mitochondria and chloroplast have to a prokaryote
- ● Theory states that an early eukaryote cell engulfed a prokaryote cell
○ Prokaryotic cell became an endosymbiont (cell that lives in another cell)
○ Became one functional organism

Question 26

cells need a ____ surface area to volume ratio to ____

Answer 26

high, optimize the exchange the material through the plasma membrane

Question 27

Larger cells have a _____ SA-V

Answer 27

lower, LOSE efficiency exchanging materials

Question 28

What happens when there is a large cell?

Answer 28

• the cellular demand for resources increase
• rate of heat exchange decreases

Question 29

Phospolipids are ____

Answer 29

amphipathic
(hydrophilic head n hydrophobic tail and form a bilayer)

Question 30

integral proteins

Answer 30

Proteins that are embedded into the lipid bilayer
- (transmembrane proteins)
- amphipatic

Question 31

Peripheral proteins

Answer 31

The proteins of a membrane that are not embedded in the lipid bilayer; loosely bound to the surface of the membrane.

Question 32

why are membrane carbohydrates important?

Answer 32

cell-to -cell recognition

Question 33

What is plasmodesmata?

Answer 33

Hole like structures in the cell wall filled with cytosol that connect adjacent cells

Question 34

What is tocinity?

Answer 34

the ability of an extracellular solution that causes a cell to gain or lose water.

Question 35

Osmoregulation

Answer 35

cells must be able to regulate their solute concentrations and maintain water balance

Question 36

in hypertonic water will move to the

Answer 36

to the extracellular fluid
effect: cells shrivel and die

Question 37

Plasmolysis

Answer 37

vacuole shrinks and the plasma membrane will pull away from the cell wall

Question 38

In hypotonic what happens to animal and plant cells?

Answer 38

Animal Cells: lyse and swell
Plant cells: cells work optimally (maintain turgor pressure)

Question 39

What are things that can easily can passed across the membrane?

Answer 39

small nonpolar, hydrophobic molecules such as Hydrocarbons, N2, CO, and O2

Question 40

What are things that are difficult to pass across the membrane?

Answer 40

Hydrophilic, polar, large molecules, ions such as sugars and water

Question 41

two categories of transport proteins

Answer 41

channel and carrier
-each transport protein is specific for substances it can facilitate movement for

Question 42

What are Sodium-Potassium Pumps

Answer 42

Animal cells will regulate their relative concentrations of Na+ and K
- 3 Na+ get pumped out of the cell
- 2 K+ get pumped into the cell
- Results in a +1 net charge to the extracellular fluid

Question 43

Plants use contrasport for

Answer 43

sugars and amino acids
EX: sucrose-H+ cotransporter
-Sucrose can travel into a plant cell against its concentration gradient ONLY if it is coupled with H+ that is diffusing down its electrochemical gradient

Question 44

Exocytosis

Answer 44

the secretion of molecules via vesicles that fuse to the plasma membrane

Question 45

endocytosis

Answer 45

the uptake of molecules from vesicles fused to the plasma membrane

Question 46

Phagocytosis

Answer 46

when a cell engulfs particles to be later digested by lysosomes

Question 47

Pinocytosis

Answer 47

nonspecific uptake of extracellular fluid containing dissolved molecules

Question 48

receptor-mediated endocytosis

Answer 48

specific uptake of molecules via solute binding to receptors on the plasma membrane

Question 49

what is favorable and unfavorable movement?

Answer 49

• Favorable movement: downhill diffusion
• Unfavorable movement: uphill transport

Question 50

covalent bonds

Answer 50

when 2 or more atoms share electrons

Question 51

nonpolar covalent

Answer 51

electrons are shared equally between two atoms

Question 52

polar covalent

Answer 52

electrons that are not shared equally

Question 53

ionic bonds

Answer 53

the attraction between oppositely charged atoms

Question 54

Cohesion

Answer 54

attraction of molecules for other molecules of the same kind
- in plants: H20 molecules stick together

Question 55

adhesion

Answer 55

the clinging of one molecule to a different molecule
- In plants, this allows water to cling to the
cell walls to resist the downward pull of gravity
- h2o molecules stick to the xylem wall

Question 56

Density (floating ice)

Answer 56

as water solidifies it expands and becomes less dense
● Due to the hydrogen bonds
● When cooled, H2O molecules move too slowly to break the bonds
○ Allows marine life to survive under floating ice sheets

Question 57

lipids are nonpolar or polar

Answer 57

nonpolar- hydrophobic

Question 58

Cholesterol

Answer 58

helps maintain fluidity at high and low temps
■ High temp: reduces movement
■ Low temp: reduces tight packing of phospholipids

Question 59

glycolipids vs glycoproteins

Answer 59

glycolipids: cholesterol bonded to lipids
glycoproteinsa: cholesterol bonded to proteins

Question 60

Passive transport

Answer 60

transport of a molecule that does not require energy from the cell because a solute is moving with its concentration gradient
ex: diffusion, facilitated diffusion, osmosis

Question 61

Channel proteins

Answer 61

provide a channel for molecules and ions to pass
aquaporins: channels for water molecules to pass by

Question 62

carrier proteins

Answer 62

undergo conformational changes for substances to pass

Question 63

examples of active transport

Answer 63

• exocytosis, endocytosis, pumps, contrasport

Question 64

proton pump

Answer 64

integral membrane protein that builds up a proton gradient across the membrane
○ Used by plants, fungi, and bacteria
○ Pumps H+ out of the cell