Biology Exam 2: Cells, Metabolism, Respiation, Photosynthesis

Front 1

Metabolism

Back 1

sum total of all chemical reactions occurring in the cell in an organism

Front 2

Catabolism

Back 2

one of the components of metabolism: metabolic pathways that release energy by breaking down complex molecules into simpler compounds (ex. cellular respiration)

Hint 2

break down

Front 3

Anabolism

Back 3

Metabolic pathways that consume energy by building complex molecules from simpler ones

Hint 3

build up

Front 4

Energy

Back 4

the capacity to do work

Front 5

kinetic energy

Back 5

energy of motion
: one of fundamental types of energy

Front 6

potential energy

Back 6

energy that matter possesses because of its structure or location
: one of fundamental types of energy

Front 7

chemical energy ( not one of two basic fundamental energies)

Back 7

type of kinetic energy: stored i nmolecules because of the structural arrangement of the atoms in those molecules

Front 8

are the basic types of energy interconvertible?

Back 8

yes

Front 9

Free energy

Back 9

that portion of a system's energy that is available to perfom work

Front 10

are free energy and process sponaneity related?

Back 10

yes

Front 11

a spontaneously occurring process will always involve...

Back 11

a loss of free energy ( delta G will be negative : energy is released)

Front 12

processes that DO NOT occur spontaneouly require...

Back 12

an input of energy if they are going to occur ( delta G will be positive: energy increases)

Front 13

Exergonic

Back 13

free energy is released during reaction

Hint 13

1 of fund. types of chem. reactions in metabolism

Front 14

Endergonic

Back 14

free energy is absorbed during reaction

Front 15

are exergonic and endergonic reactions coupled in metabolism?

Back 15

yes

Front 16

ATP

Back 16

Adenosine Triphophate
Contains potential chemical energy
- the molecule that is used to carry out most cellular work

Front 17

what ultimately allows work to be performed?

Back 17

the hydrolysis of the phosphate bonds is an exergonic reaction that is coupled to endergonic reactions
: ex : active transport, ATP hydrolysis, changes in protein shape (confirmation)
8.14

Front 18

Mechanical work

Back 18

changes in shape ; movement
: one of 3 basic types of cell work

Front 19

transport work

Back 19

movement of substancecs across the embrance against the concentration gradient
:1 of 3 cell work

Front 20

chemical work

Back 20

pushing of endergonic reactions )in most cases this pushing coupled o exergonic reactions)
: 1 of 3 cell work

Front 21

Enzymes are what?

Back 21

protein catalysts

Hint 21

2 words

Front 22

catalyst

Back 22

an chemical agent (like protein) that changes the rate of how fast a chemical reaction occurs withouth being consumed in the reaction
:does not change spontanaeity

Front 23

enzymes work by lowering what?

Back 23

energy of activation in a chemical reaction
: this increases the rate of the reaction (ho fast occurs) so that the normal metabolism of the cell cna be maintained; however, enzymes do not have capacity by themselves to make nonspontaneous reactions occur (this requires energy)

Front 24

enzymes allow less energy to activate reaction

Back 24

goes from high energy to low energy and reuses recycled enzymes

Front 25

enzymes are substrate specific

Back 25

3D fit between an enzyme and its substrate and "induced fit"

Front 26

induced fit

Back 26

a slight change in the active site of a protein upon binding of substrate such that the binding affinity is increased

Front 27

active site

Back 27

key part:
where the chemistry occurs
:catalytic center of enzyme
:part(s) of the substrate molecule(s) to be effected are held in close proximity

Front 28

will the internal environment of the cell affect enzyme activity?

Back 28

yes
:important environmental factors include:
pH (acidity), temperature, cofactors like vitamins

Front 29

Control of Metabolism:
Competitive Binding

Back 29

a molecule that directly affects active site by competitive binding will have an overall shpare tha tis similar to the substrate

Front 30

Control of Metabolism:
Noncompetive Binding

Back 30

indirectly affects active site by binding a site away from the active site, but overall protein shape is changed as is the conformaion of the active site

Front 31

Control of Metabolism:
Allosteric Regulation

Back 31

allosteric enzymes are typically composed of several subunits; binding to the allosteris sie )away from the active site) may simultaneously change all active sites of the individual subunites such that the enzyme is activated or inhibited

Front 32

Control of Metabolism:
Cooperativity

Back 32

binding of a single substrate molecule to one of several subunits results in induced fit and activation of active sites on other subunits

Front 33

Control of Metabolism:
Notes

Back 33

Feedback inhibition of a metabolic pathway - localization of enzymes w/in the cell

Front 34

Cellular Respiration

Back 34

metabolic process by which organisms convert the energy present in organic molecules to ATP and byproducts

Front 35

Glucose: Summary Equation

Back 35

Organic Molecule + Oxygen = CO2 + H2O + ATP + HEAT

Front 36

mitochondrial structure

Back 36

outer membrane, inner membrane, intermembrane space, matrix

Front 37

3 parts of cellular respiration:
oxidative phophorylation

Back 37

generates most of the ATP

Front 38

3 parts of cellular respiration:
glycolysis

Back 38

occurs in the cytosol; generates 2 ATP and some high energy molecules (2 NADH) that will drive oxidative phosphorylation

Front 39

3 parts of cellular respiration:
krebs cycle

Back 39

occurs in the mitochonrial matrix; generates some ATP(2) and alot of high energy molecules (10) that will be used to drive oxidative phos.

Front 40

oxidative phosphorylation

Back 40

Oxidation/Reduction reactions and the pumping of protons across the inner membrane of the mitochondrion

Front 41

Oxidation/Reduction (Redox) Reactions

Back 41

involves the transfer of electrons from one molecule to another

Front 42

oxidized

Back 42

the molecule that losses electrons:
(LEO, loss of electrons is oxidation

Front 43

reduced

Back 43

the molecule that gains electrons:
GER = (Gain of electrons is reduction)

Front 44

X(e-) + Y ------------> X + Y(e-)

Back 44

in this example, molecule X is the reducing agent (which is oxidized) and molecule Y is the oxidizing agent (which is reduced)

Front 45

when electrons are transferred between molecules they lose ...

Back 45

some enrgy with each transfer

Front 46

what are pumped from matrix side of the mito to the inner membrane side by a hydrogen-electron transport chain (HETS)?

Back 46

protons (H+)

Front 47

HETS

Back 47

series of proteins located within or on the inner membrane that function in a series of redox reactions

Front 48

as e- move through the HETS chain they progressively ...

Back 48

lose energy,

Front 49

some of this energy is used to transport WHAT across the membrane?

Back 49

H+

Front 50

when a protein in the chain receives e- (is reduced) it gains energy, but losses energy when it is oxidized

Back 50

the HETS is a series of exergonic and endergonic reactions that are coupled

Front 51

certain proteins in the HETS will use the free enrgy that accompanies the redox reaction to do WHAT?

Back 51

to transfer eletrons across the inner membrane

Front 52

In the HETS, the proteins are organized in such a way that there is a...

Back 52

continnuum of increasing electronegativity; this results in the orderly flow of electrons “downhill” toward a terminal electron acceptor (oxygen)

Front 53

The initial electron donors in oxidative phosphorylation are...

Back 53

high energy reducing agents that are generated in the Krebs cycle and in Gylcolysis

Front 54

How many reducing agents are used??

Back 54

2: (NADH, and FADH2 are used)

Front 55

How many protein complexes comprise the HETS?

Back 55

3: (NADH-Coenzyme Q Reductase, Coenzyme Q -Cytochrome C Complex, Cytochrome C Oxidase Complex)

Front 56

Do electrons flow sequentially through these complexes?

Back 56

Yes

Front 57

each complex is comprised of many ...

Back 57

proteins, but only a few of these proteins actually function in the transfer of protons across the inner membrane

Front 58

these electrons are transferred through the complxes with a particular # of H+ being transfered by some of the proteins of the respective complexes

Back 58

NADH-Coenzyme Q Reductase - 4H+

Coenzyme Q -Cytochrome C Complex - 6H+

Cytochrome C Oxidase Complex - 2H+

Front 59

Note that each NADH transfers 2e- through each of these complxes and is therefore responsible for the movement of 12H+ across the inner membrane

Back 59

 In contrast FADH2 initially donates 2e- to Coenzyme Q -Cytochrome C Complex and is ultimately responsible for the movement of 8e- across the membrane

Front 60

Note that oxygen is the terminal electron acceptor in the formation of water

Back 60

2e- + 2H+ + 1/2O2 ------> H2O

Front 61

protomotive force

Back 61

The proton gradient that results
pmf = concentration gradient + charge speration (voltage potential)
*most of the potential energy of the protomotive force is embodied in the charge potential

Front 62

Use of PMF to Generate ATP:
ATP Synthase Complex (mitochondrial lollipops)

Back 62

a large complex of protiens that has two major components (a stem called Fo and a head called F1 that actually synthesizes ATP from ADP + Pi)

Front 63

as eletrons flow through channels in Fo conformational changes occur in F1 that lead to the generation of...

Back 63

ATP

Front 64

for every 4H+ that move through how many ATP molecules are generated?

Back 64

1

Front 65

Krebs Cycle

Back 65

occurs in the matrix of the mito., generates NADH, FADH2, and some ATP, as well as CO2 as a byproduct

Front 66

pyruvate

Back 66

starting molecule that enters the Krebs cycle

Front 67

for each pyruvate the cycle will generate ?? NADH, ??FADH2, ?? ATP, and the ?? CO2

Back 67

4 NADH, 1 FADH2, 1ATP, and the 3CO2

Front 68

For each starting glucose, ?? pyruvate are generated during glycolysis;

Back 68

2

Front 69

per glucose the Krebs cycle generates:

• 6CO2 as byproducts
• 8 NADH = 24 ATP equivalents
• 2 FADH2 = 4 ATP
• 2 ATP are drectly produced

Back 69

for a total yield 30 ATP equivalents from the Krebs cycle

Front 70

Glycolysis

Back 70

splitting of glucose into two three carbon molecules with the release of energy; occurs in the cytosol and the endproduct (pyruvate is transported into the mitochondrion); no oxygen is required

Front 71

glucose is split into two glyceraldehyde 3-phospahte molecules (with several intermediate molecules and each step catalyzed by enzymes)

Back 71

note that included in these reactions is the addition of two phospahte groups, so two ATP molecules are consumed in these initial reactons (energy of activation)

Front 72

each glyceraldehyde 3-phospahte then has an inorganic phospahte added (no ATP consumed);

Back 72

this addition is highly exergonic and is coupled to the reduction of NAD+; the product of this step is 1,3 bisphosphoglycerate

Front 73

each 3 phosphoglycerate is converted to pyruvate and a single molecule of ATP is produced via substrate level phosphorylation

Back 73

each 1,3 bisphosphoglycerate is then dephopsphorylated in substrate level phosphorylation to produce a molecule of ATP; the product is 3 phosphoglygerate

Front 74

Summary - Products and byproducts

Back 74

A. Gylcolysis - 2 NADH + 2 ATP
B. Krebs Cycle - 8 NADH + 2FADH2 + + 2ATP + 6CO2
C. Oxidative Phosphorylation - 34 ATP + 12 H2O (O2 consumed)
D. C6H12O6 + 6O2 -------> 38 ATP + 6CO2 + 6H2O

Front 75

Cellular Respiration and Physiological Conditios (with respect to O2)

Back 75

Pyruvate is a key intermediate.

Front 76

Krebs Cycle

Back 76

occurs in the matrix of the mito., generates NADH, FADH2, and some ATP, as well as CO2 as a byproduct

Front 77

pyruvate

Back 77

starting molecule that enters the Krebs cycle

Front 78

for each pyruvate the cycle will generate ?? NADH, ??FADH2, ?? ATP, and the ?? CO2

Back 78

4 NADH, 1 FADH2, 1ATP, and the 3CO2

Front 79

For each starting glucose, ?? pyruvate are generated during glycolysis;

Back 79

2

Front 80

per glucose the Krebs cycle generates:

• 6CO2 as byproducts
• 8 NADH = 24 ATP equivalents
• 2 FADH2 = 4 ATP
• 2 ATP are drectly produced

Back 80

for a total yield 30 ATP equivalents from the Krebs cycle

Front 81

Glycolysis

Back 81

splitting of glucose into two three carbon molecules with the release of energy; occurs in the cytosol and the endproduct (pyruvate is transported into the mitochondrion); no oxygen is required

Front 82

glucose is split into two glyceraldehyde 3-phospahte molecules (with several intermediate molecules and each step catalyzed by enzymes)

Back 82

note that included in these reactions is the addition of two phospahte groups, so two ATP molecules are consumed in these initial reactons (energy of activation)

Front 83

each glyceraldehyde 3-phospahte then has an inorganic phospahte added (no ATP consumed);

Back 83

this addition is highly exergonic and is coupled to the reduction of NAD+; the product of this step is 1,3 bisphosphoglycerate

Front 84

each 3 phosphoglycerate is converted to pyruvate and a single molecule of ATP is produced via substrate level phosphorylation

Back 84

each 1,3 bisphosphoglycerate is then dephopsphorylated in substrate level phosphorylation to produce a molecule of ATP; the product is 3 phosphoglygerate

Front 85

Summary - Products and byproducts

Back 85

A. Gylcolysis - 2 NADH + 2 ATP
B. Krebs Cycle - 8 NADH + 2FADH2 + + 2ATP + 6CO2
C. Oxidative Phosphorylation - 34 ATP + 12 H2O (O2 consumed)
D. C6H12O6 + 6O2 -------> 38 ATP + 6CO2 + 6H2O

Front 86

Cellular Respiration and Physiological Conditions (with respect to O2)

Back 86

Pyruvate is a key intermediate.

Front 87

Photosynthesis

Back 87

the generation of carbohydrate using light energy:
Requires carbon dioxide and water as reactants - Byproducts are oxygen and water

Front 88

Photosynthesis Summary Equation

Back 88

6CO2 + 12H2O -----> C6H12O6 + 6O2 + 6H2O

Front 89

the ????? of CO2 is incorporated into carbohydrate using high energy molecules produced using sunlight energy

Back 89

carbon

Front 90

what drives an electron trnsport chain that is used to make these high energy molecules?

Back 90

sunlight

Front 91

what comes from the water moleule (splitting of water)?

Back 91

oxygen

Front 92

what are the primary photosynthetic organs of plants?

Back 92

leaves

Front 93

what are the organelles within which photosynthesis occurs?

Back 93

cholorplasts

Front 94

chloroplasts contain chlorophyll which is...

Back 94

a pigment which is capable of absorbing sunlight energy

Front 95

there are HOW MANY types of chlorophyll molecules?

Back 95

3 : each having slightly different absorption characteristics

Front 96

(most land plants have ....

Back 96

both chl. a and b

Front 97

chlorophyll molecules are organized into photosystems on the

Back 97

thylakoid membranes

Front 98

the photosystem consists of

Back 98

antennae chlorophyll molecules, a rection center chlorophyll, and associated proteins

Front 99

WHAT is transferred from the antennae chlorophyll molecules to the reaction center chlorophyll where WHAT begins?

Back 99

light energy - electron transport

Front 100

Light Reactions

Back 100

1. require light
2. occur on the surface of the thylakoids
3. generate ATP and NADPH
4. require H2O and release O2 as a by product
5. involves a electron trnsport chain similar to that of cellular respiration

Front 101

The light reactions involve the coordinated action of two WHAT?

Back 101

photosystems: PS 1 AND PS 2

Front 102

cyclic electron flow

Back 102

produces nearly equal quanties of ATP and NADPH as well as consumes H2O and produces O2 as a by product

Front 103

noncyclic electron flow

Back 103

(from Fd of PSI to Cyt C of PSII) produces ATP only

Front 104

PSII

Back 104

1. has the OEC and thus consumes H2O and liberates O2
2. generates the protomotive force (ATP synthesis)

Front 105

PSI

Back 105

1. receives e- from PSII and produces NADPH

Front 106

The Calvin Cycle

Back 106

(light independent reactions)
1. can occur in either the light or dark
2. uses the high energy molecules produced in the light reactions to make carbohydrate

Front 107

Cell Wall (Plant Cells)
Function

Back 107

protection, maintains cell shape, support

Front 108

Cell Wall Structure

Back 108

1. the cell wall of higher plants is composed of numerous overlapping cellulose fibers

Front 109

Primary Type of Cell Wall

Back 109

thin and pliable, and allows for growth of the cell; produced first as the cell matures

Front 110

Secondary Cell Wall

Back 110

much more rigid and thicker than primary cell wall; produced after the primary wall

Front 111

Plasma Membrane Function

Back 111

1. regulates the passage of substances into and out of the cell
2. is selectively permeable

: certain small molecules will diffuse across the PM (O2, CO2, H2O):

Front 112

Plasma Membrane Structure

Back 112

1. is fundamentally a phospholipid bilayer that contains some associated protein
2. the membrane is structurally dynamic (the functional membrane is somewhat like a fluid or gel)

Front 113

Movement Across Membranes:
diffusion

Back 113

spontaneous movement of molecules down a concentration gradient

Front 114

Movement Across Membranes:
osmosis

Back 114

diffusion of water across the membrane
 unlike solute, water moves from hypotonic to hypertonic solutions

Front 115

facilitated diffusion

Back 115

protein assisted
 allows larger as well polar molecules to cross the PM down a concentration gradient

Front 116

diffusion, fac. diffusion, and osmosis are...

Back 116

passive processes (passive transport)

Front 117

Active transport

Back 117

requires energy (ATP) and proteins in order to occur; substances are moved against their concentration gradient

Front 118

Nucleus

Back 118

The largest and most conspicuous organelle
B. Enclosed by a double membrane that comprises the nuclear envelope

Front 119

Nucleus' Nuclear Envelope

Back 119

has pores that regulated the movement of molecules into and out of the nucleus

Front 120

The nucleus contains most of the cell’s DNA in the form of chromatin

Back 120

chromatin = DNA + bound protein

Front 121

Ribosomes

Back 121

. Site of protein synthesis
B. May occur freely or bound to membranes of the ER

Front 122

Endomembrane System

Back 122

an integrated set of membranes within the eukaryotic cell (integrated = they work together to accomplish certain functions and, in some cases, are physically joined
:these membranes are “integrated” in that they are physically joined or communicate through vesicles:

Front 123

vesicle

Back 123

a “packet “of substances that are surrounded by a membrane

Front 124

Endomembrane System consists of...

Back 124

consists of the nuclear membrane, endoplasmic reticulum, golgi apparatus, lysosomes, and vacuoles

Front 125

Endoplasmic Reticulum (ER)

Back 125

A. A complex of membranes folded into sac-like structures that are joined with the nuclear membrane

Front 126

2 Types of ER:
Smooth
Rough

Back 126

Smooth - no bound ribosomes
Rough - has bound ribosomes

Front 127

Functions of the ER

Back 127

 Synthesis of phospholipids (Smooth ER)
 Breakdown of drugs and other toxic substances
 Manufacture of proteins that will be secreted outside the cell or deposited in the plasma membrane

Front 128

Golgi Apparatus (GA)

Back 128

Made of flattened sacs (cisternae) that modifies, stores, and routes products from the ER

Front 129

Functions of the GA

Back 129

chemical modification of proteins and phospholipids synthesized in the ER
• directs proteins, phospholipids, and other molecules to other places in the cell

Front 130

Lysosomes

Back 130

A membrane enclosed bag of hydrolytic (digestive) enzymes
- enzymes within lysosomes are capable of digesting almost any kind of molecule

Front 131

Functions of Lysosomes

Back 131

intracellular digestion
• recycling of macromolecules within the cell
• programmed cell destruction

Front 132

Vacuoles (Plants)

Back 132

A compartment (usually large) that is membrane bound

Front 133

Vacuoles function in:

Back 133

storing food (formed by phagocytosis)
2. pumps (contractile vacuoles)
 storage (central vacuoles of plants)

Front 134

Mitochondria

Back 134

-"powerhouse" of the cell (site of ATP production)
Organic molecule + oxygen = CO2 + H2O + ATP + Heat

Front 135

Chloroplast

Back 135

site of photosynthesis:
Light + CO2 + H2O = carbohydrate + oxygen

Front 136

Cytoskeleton

Back 136

a network of fibers that forms a framework for support, provides a means for movement, and enables a cell to maintain and change shape

Front 137

Peroxisomes

Back 137

. organelles that contain enzymes that metabolize oxygen and peroxide
B. additional functions include:
- breakdown of fatty acids
- detoxification of alcohol and other toxic substances

Front 138

Hypertonic Solution:

Back 138

Solute concentration higher than cell
More dissolved particles outside of cell than inside of cell
Hyper = more (think hyperactive); Tonic = dissolved particles
Water moves out of cell into solution
Cell shrinks

Front 139

Hypotonic Solution:

Back 139

Solute concentration lower than cell
Less dissolved particles outside of cell than inside of cell
Hypo = less, under (think hypodermic, hypothermia); Tonic = dissolved particles
Water moves into cell from solution
Cell expands (and may burst)

Front 140

Solute

Back 140

dissolved particle

Front 141

Solvent

Back 141

liquid medium in which particles may be dissolved