bio midterm

Question 1

what are the Similarities and differences between prokaryotes and eukaryotes? Specifically, differences between bacteria and humans

Answer 1

Eukaryotic cells contain membrane-bound organelles, including a nucleus. Eukaryotes can be single-celled or multi-celled, such as you, me, plants, fungi, and insects. Bacteria are an example of prokaryotes.

Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle.

eukaryotes are larger and more complex but both have ribosimes

Question 2

what are The components of a nucleotide?

Answer 2

A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base

Question 3

what are isotopes

Answer 3

Isotopes are two atoms of an element that differ in number of
neutrons

Question 4

non-polar covalent bonds:

Answer 4

Electrons are shared evenly

Question 5

Polar covalent bonds:

Answer 5

More electronegative atom pulls the electrons closer to its nucleus

Question 6

The type of bonds which lead to a molecule being hydrophobic or hydrophilic

Answer 6

water =polar
methane = non-polar covalent
carbon dioxide = polar covalent

1 sugar
2 nitrogines base
3 phospate group

Question 7

Limits to cell size, specifically the details regarding surface area to volume ratios

Answer 7

as a cell gets larger there’s more internal space that need to be serviced by the surface of the cell

but the surface of the cell doesn’t grow as fast as the internal volume

Question 8

Lipid fluidity, what type of bonds increase or decrease fluidity, and what type of lipids are liquid at room temperature

Answer 8

there are two different arrangements around the double bond that can happen

which makes kinks = cis

which makes it straight = trans

the trans bond the opposite doesnt have to worry about it

phospholipids that have more cis bonds cause more fluid

and membrane that has fatty acid in a phospholipid will have a bunch of cis bonds will have more fluid because it pushes it apart and causes more fluidity

Question 9

Cis-trans isomers, what makes them differ

Answer 9

cis isomers have the same connectivity to atoms and similar side groups that are placed on the same side of the double bond

trans isomers are molecules having similar side group placed on opposite sides of the double bond

Question 10

Dehydration reactions and hydrolysis

Answer 10

donates H+ removes acid and base

Question 11

Valence electrons, how many electrons fit into the innermost orbital and the outer orbitals

Answer 11

5 electrons

Question 11

Be able to calculate hydroxyl ion concentrations given a pH value, and vice-versa

Answer 11

The pH + pOH = 14
The pOH = -log[OH-]
The pH is measure of acidity of a solution whereas the pOH is a measure of basicity of a solution.
The two expressions are opposites expressions. As the pH increases the pOH decreases and vice versa. Both values equal 14.
To convert a concentration of into pH or pOH take the -log of molar concentration of the hydrogen ions or the molar concentration of the hydroxide ion concentration respectively.
pH = -log [ H+]
pOH = -log [OH-]
For example if the [OH-] = 0.01 M, the -log [0.01 ] = 2.0
This is the pOH.
To determine the pH perform the following calculation.
pH = 14.0 - 2.0
pH = 12.0

Question 12

Be able to tell the different types of isomers apart based on diagrams of their structure

Answer 12

structural switch up the bond order they are just rearrangements same number of atoms but the bonding order is different

geometric differ on sides of double bond

entiomters mirror image of each other

cis = same makes the kinks

Question 13

Starch and cellulose, what makes them different, and what makes them similar

Answer 13

starch

cellulose

the bonds between the glucose molecules are different

starch is easier to beak down energy

cellulose isnt gonna be easy to beak down
structure

Question 14

How phospholipids interact with water molecules

Answer 14

phospholipids are amphipathic
has a polar or hydrophilic head and has a nonpolar or hydrophobic tail

look at the diagram on the lecture slides

the tails will be repelled and the head will be attracted

they have polar and non-polar domains which makes them amphipathic molecules has a hydrophobic tail and a hydrophilic tail
amphipathic (MEMORIZE)

Question 15

Organelles (like the central vacuole) that plant cells have which animal cells do not. Be sure to know their function

Answer 15

figure out which one is which and differ them from each other

https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.britannica.com%2Fscience%2Fplant-cell&psig=AOvVaw1SdmIp0lI6kcTFWX47m9am&ust=1721347785779000&source=images&cd=vfe&opi=89978449&ved=0CBEQjRxqFwoTCMjjqq2mr4cDFQAAAAAdAAAAABAE

https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.geeksforgeeks.org%2Fanimal-cell%2F&psig=AOvVaw3kh5t4oF1699KV_shA3ZvU&ust=1721347865526000&source=images&cd=vfe&opi=89978449&ved=0CBEQjRxqFwoTCICWrdOmr4cDFQAAAAAdAAAAABAQ

Question 16

Given a list of cellular components (like organelles), be able to identify if it is from a plant, animal, or bacterium

Answer 16

plant =dna , nucleus , ribosomes, phospholipidbilayer , chloroplasts ,membrane bound organelles , Golgi

animal =dna , nucleus , ribosomes , cell membrane phospholipidbilayer , no chloroplasts ,membrane bound organelles , Golgi

bacteria =dna , no nucleus , ribosomes , cell membrane , no chloroplasts , phospholibidbilayer, no membrane bound organelles , no Golgi

this is the only info needed for the answer to the question

Question 17

Understand plasmodesmata and what they do in the plant

Answer 17

the holes between the cells
they maintain continuity between adjacent cells

in the cell walls pores in the cell wall that allow passage of things from cell to cell

Question 18

Integral membrane proteins and how they anchor into the plasma membrane

Answer 18

= they have to have a domain of hydrophicity
and hydrofilizane domain , the part thats in the phospholipid bilayer needs to be

it should be primary amino acids in the

on the top it should be primarily polar amino acids and on the bottom too

it should have polar and non-polar regins

polar makes it hydrophilic

Question 19

Osmosis, is it passive or active, where does it occur, and in which direction does water move relative to concentrations of solute

Answer 19

passive or active
= it is passive
it is just diffusion of water molecules

where does it occur =
across membranes across semipermial membranes . membranes that allow water to pass

where does it occur, and in which direction does water move relative to concentrations of solute
= the water is the solvent
moving from high concentration of water to lower concentration but a higher level of solute

until the two solutions become isotonic water will keep moving

Question 19

How likely molecules are to diffuse through a phospholipid bilayer based on their size and hydrophobicity of hydrophilicity

Answer 19

50% chance is the domain of hydrophobicity

Question 19

Anabolic vs catabolic pathways, do they build up or break down polymers, and do they release or consume energy

Question 20

How membranes can maintain fluidity in cold temperatures

Answer 20

if unsaturated fatty acids are compressed the kinks in their tails push adjacent phospholipid molecules away

Question 21

ΔG values, what does a positive or negative value mean, especially relating to exergonic or endergonic reactions

Answer 21

Reactions with a negative ∆G release energy, which means that they can proceed without an energy input (are spontaneous). In contrast, reactions with a positive ∆G need an input of energy in order to take place (are non-spontaneous).

Question 22

ATPase, the pumps which can move ions against concentration gradients. If given a question regarding concentrations of ions, be able to tell if ATPase is pumping ions, and in which direction.

Answer 22

What is the pumping of ions against a concentration gradient using ATP?
- Active transport: moving against a gradient

To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells.

Question 23

How competitive and noncompetitive inhibitors decrease the rate of enzyme-catalyzed reactions

Answer 23

only the inhibitor or the substrate can be bound at a given moment. In noncompetitive inhibition, the inhibitor doesn’t block the substrate from binding to the active site.

Question 24

If given an equation for a reaction, be able to identify which molecules were oxidized and reduced. Remember that when something is reduced it usually gains an electron and a hydrogen

Answer 24

oxidation is the loss of electrons and reduction is the gain of electrons

NaCl + e^- —-> NaCl
NaCl —–> NaCl +e^-

Question 24

Redox reactions, what happens to the reducing and oxidizing agents in the reaction? Remember that gaining an electron usually also means the molecule gains potential energy

Question 25

Where the oxygen produced by photosynthesis comes from

Answer 25

the oxygen released during photosynthesis is from the water, plants will absorb water as well as co2 during photosynthesis

Question 26

Chemiosmosis and oxidative phosphorylation, how one powers the other

Answer 26

The energy released in these reactions is captured as a proton gradient, which is then used to make ATP in a process called chemiosmosis.

Question 27

The role of oxygen in cellular respiration

Answer 27

to act as the electron acceptor

Question 28

How the energy released by transfer down the electron transport chain between photosystems 2 and 1 is used

Answer 28

to generate a proton gradient across the thylakoid membrane

Question 29

How puncturing of a thylakoid membrane would affect key processes of photosynthesis (splitting water, reduction of NADP+, ATP synthesis, electron flow)

Answer 29

it would disturb the membrane potential all across the membrane and effect flow of protons into and out of the cell

Question 30

pH, how much of a change in concentration of hydrogen ions is indicated by a change in pH value of 1

Answer 30

pH =4 1x 10^-4 mol/L
pH =5 1 x10^-5 mol/L
this means the concentration of hydrogen ions [H+] the number is the inverse log of the molar concentration of the hydrogen atom

the question is how much does to change in concentration in pH by a value of 1

1x 10^-4 mol/L
0.0001
1 x10^-5 mol/L
0.00001

the more zeros the smaller it is
ph 4 has a higher concentration as to pH 5

pH 5 has 1/10 concentration as pH 4

pH 5 has one more zero than pH 4

Question 31

The source of charge in atoms, what situation results in an atom without any charge

Answer 31

when they have a charge its a ion

Question 32

Nonpolar covalent bonds, polar covalent bonds, hydrogen bonds. How does electronegativity affect the type of bond between atoms

Answer 32

Intra-molecular forces theuy occur between atoms hydrogen bonds occur during m olecules during highly po;ar molecules

Question 33

what are lysosomes

Answer 33

Some types of cell can
engulf another cell by
phagocytosis; this
forms a food vacuole
* A lysosome fuses with
the food vacuole and
digests the molecules
Lysosomes: Phagocytosis

Question 34

what is entropy

Answer 34

Entropy is a measure of
randomness or disorder in
a system. Gases have
higher entropy than
liquids, and liquids have
higher entropy than solids.

Question 35

exergonic reactions

Answer 35

release energy

Question 36

endergonic reactions

Answer 36

require energy

Question 37

ATP synthesis

Answer 37

requires energy

Question 38

ATP hydrolysis

Answer 38

releases energy

Question 39

Enzymes speed up…..

Answer 39

Enzymes speed up the cell’s chemical
reactions by lowering energy barriers

Question 40

catabolic :

Answer 40

energy is being realized because you go from high-energy reactants to low-energy reactant product

Answer 41

oxygen = terminal electron (e^-) acceptor in reparation

oxygen is very electronegative

Question 42

The Stages of Cellular Respiration:
A Preview

Answer 42

1. Glycolysis (breaks down glucose into two molecules of pyruvate)
2. The oxidation of pyruvate and citric acid cycle (completes the
   breakdown of glucose)
3. Oxidative phosphorylation which is both the electron transport
   chain and the process of chemiosmosis (accounts for most of the
   ATP synthesis)

Question 43

what does glycolysis do Glycolysis reduces the electron
carrier NAD+ to NADH

Answer 43

Glycolysis reduces the electron
carrier NAD+ to NADH

Question 44

oxidation phosphorylation is an umbrella for

Answer 44

• electron transport chain
• chemiosmosis
• ATP

Question 45

memorize

Answer 45

cellular respiration slide slide 45 week 3