Chapters 6-10 Bio

Front 1

What is a ligand?

Back 1

A signaling molecule required for cell communication.

Front 2

What is a receptor protein?

Back 2

Molecule to which a ligand binds.

Front 3

Does glycolosis need oxygen to carry out its function?

Back 3

No, It does not, glycolosis is anaerobic.

Front 4

Where does glycolosis occur?

Back 4

In the cytoplasm, not in any organelle

Front 5

What is glycolosis?

Back 5

Converts (breaks down) glucose into two 3-carbon molecules of pyruvate. Net total gain of ATP is 2. Net total gain of NADH is 2. all cells can do glycolosis.

Front 6

What happens in the first step (priming) of glycolysis?

Back 6

Transfers 2 phosphate from 2 ATP to the glucose molecule. Uses 2 atp.

Front 7

Autotroph?

Back 7

Self-feeder

Front 8

Heterotroph?

Back 8

An organism that feeds off organic compounds that autotrophs produce. 95 percent of organisms are autotrophs.

Front 9

Substrate level phosphorylation

Back 9

An enzyme transfers a phosphate group from an organic molecule (the substrate) to ADP, forming ATP.

Front 10

Respiration occurs in three metabolic stages:

Back 10

Glycolysis, Krebs Cycle, Electron Transport chain & Chemiosmosis.

Front 11

How many ATP molecules are derived from one glucose molecule?

Back 11

38

Front 12

Ethanol Fermentation

Back 12

Pyruvate is anaerobically converted via acetaldehyde into carbon dioxide and ethanol, this generates NAD+.

Front 13

Lactate Fermentation.

Back 13

Lactate is formed when there is inadequate oxygen present in a muscle cell undergoing contractions. For glycolysis to keep going, the NAD+ reduced in glycolysis needs to be replenished to repeat the cycle. The conversion of pyruvate to lactate regenerates and restores NAD+.

Front 14

Is co2 produced during glycolysis?

Back 14

No.

Front 15

Does glycolysis occur whether O2 is present or not?

Back 15

Yes, While it is anaerobic meaning it does not utilize oxygen, it still occurs wether o2 is present or not.

Front 16

Where does glycolysis occur?

Back 16

the cell cytoplasm

Front 17

What two steps might pyruvate continue on to if oxygen is not present? what is another function of these two.

Back 17

Lactate fermentation and ethanol fermentation, this also recycles NADH into NAD+ so glycolosis can continue.

Front 18

oxidation of glucose does what to molecules of NAD+?

Back 18

reduces them to NADH. 2 molecules btw.

Front 19

What is the next step for the two pyruvate molecules after glycolysis?

Back 19

pyruvate moves to the Krebs cycle and the energy stored in NADH can be converted to ATP by the electron transport system and oxidative phosphorylation.

Front 20

How much of the original energy in glucose is still present in two molecules of pyruvate.

Back 20

more than three quarters.

Front 21

Where does the krebs cycle take place?

Back 21

mitocondria

Front 22

How is pyruvate transformed in the mitochondria.

Back 22

multienzyme complex modifies pyruvate into acetyl CoA as it enters the mitochondria.

Front 23

What three steps take place in order to transform pyruvate into Acetyl CoA.

Back 23

1.A carboxyl group is removed as Co2.
2. A pair of electrons is transferred to NAD+ to form NADH
3. The remainder combines with coenzyme A to form Acetyl-CoA

Front 24

What are the major end products of one turn of the krebs cycle?

Back 24

2 Co2 Released as waste, 3 NADH, 1 FADH2, 1 GTP which produces 1 ATP by substrate level phosphorylation.

Front 25

How many turns of the krebs cycle are needed for each glucose molecule?

Back 25

in glycolysis glucose breaks down into 2 pyruvate molecules so 2 turns of the krebs cycle occur.

Front 26

How are the molecules broken down during the krebs cycle?

Back 26

Oxidation takes place in the eight steps each step catalyzed by a distinct enzyme, NAD and FAD are reduced in redox reactions.

Front 27

knowing that 2 pyruvate molecules are produced from one glucose molecule how many products are produced in the krebs cycle from ONE pyruvate?

Back 27

4 NADH (1 from acetyl CoA conversion and 3 from Krebs cycle)
1 FADH2
1 GTP (produces 1 ATP via substrate level phosphorylation)
3 CO2 (1 from acetyl CoA conversion and 2 from Krebs cycle

Front 28

Per one molecule of glucose how many atp are produced at the end of the krebs cycle, and where does the remaining energy go?

Back 28

only 4 out of the 38 total are derived from substrate level phosphorylation, the remaining majority is stored in electrons carried by NADH and FADH2, these are used to power atp synthesis via oxidative phosphorylation

Front 29

chemiosmotic coupling

Back 29

The linkage between Electron transport, ATP synthesis, proton pumping

Front 30

Chemiosmosis

Back 30

uses energy stored in from of hydrogen ion gradient across a membrane to synthesize ATP, greatest amount of chemical energy being generated directly.

Front 31

Electron Transport Chain

Back 31

Present in many copies in inner mito membrane, consists of 4 main protein complexes, also called respiratory chain, Contains over 40 proteins, 15 involved in transport. Most in lipid bilayer, hard to study due to the fact that they function only in intact membrane.

Front 32

Each respiratory complex:

Back 32

couples energy released by electron transfer across it to pump protons from water in the mitochondrial matrix into intermembrane space
2. Creates electrochemical proton gradient across the inner mitochondrial membrane

Front 33

What is the first stop for the electrons carried by NADH in the ETC?

Back 33

Flavoprotein it has a high affinity e acceptor

Front 34

how is the ETC energetically favorable for electrons?

Back 34

Each protein in the ETC has increasing affinity for electrons shuttling them along while releasing energy.

Front 35

What is the final electron acceptor?

Back 35

final electron acceptor is oxygen- combine with 2 H+ to produce water
(aerobic respiration)

Front 36

Electron transport proteins are..

Back 36

proteins containing iron-sulfur (Fe-S) centers
cytochrome proteins (Cyt-c) (contain iron atoms attached to protein heme groups)
One lipid carrier (ubiquinone- Q) that shuttles electrons along the lipid bilayer.

Front 37

What are consequences of active pumping of protons?

Back 37

Generates a gradient of proton (H+) concentrations (a pH gradient) across inner membrane

2. Generates membrane potential across inter membrane with the inside (matrix side) negative and outside positive due to outflow of protons (H+)

Front 38

ATP synthase

Back 38

1. As hydrogen ions flow down their gradient, they can only enter back into the matrix through the cylinder portion and attached rod of ATP synthase causing this portion to rotate.
2. The spinning rod causes a conformational change in the knob region, activating catalytic sites where ADP and inorganic phosphate combine to make ATP.

Front 39

Why are positively charged protons attracted to the mitochondrial matrix?

Back 39

the matrix is negative compared with the intermembrane space.

Front 40

Regulation of pathways.

Back 40

1. Rxns in each pathway are catalyzed by specific enzymes, many of which are controlled allosterically by feedback inhibition.

Front 41

do proteins fats and carbs enter metabolic pathways at the same site?

Back 41

No they enter at different sites.

Front 42

What are proteins broken down into?

Back 42

Amino Acids, then the amino groups are removed turning into molecules to be used in glycolysis and the krebs cycle.

Front 43

Why are leaves green?

Back 43

Chlorophyll molecules of chloroplast absorb violet blue and red light
These colors are most effective in driving photosynthesis
These colors reflect and transmit green light.

Front 44

What is critical for converting light into energy

Back 44

The thylakoids, flattened sacs, stacked into granum

Front 45

Where do the light and dark reactions occur in the chloroplast?

Back 45

Light rxns. occur in thylakoid and Calvin (dark) rxn. occurs in stroma

Front 46

What are the reactants and products in photosynthesis?

Back 46

6 C02 + 12 H2O + Light Energy converted to C6H12O6 (sugar) + 6 02.

Front 47

Why is cell signaling necessary?

Back 47

Cells need to interact with their environment. E.x. cell differentiation. Multicellular organisms need their cells to communicate to coordinate the functions of the organism as a whole.

Front 48

signal transduction

Back 48

conversion of an extracellular signal to an intracellular signal.

Front 49

4 ways cells communicate?

Back 49

direct contact, paracrine signaling, endocrine signaling, synaptic signaling.

Front 50

Direct contact

Back 50

two cells in direct contact send signals across gap junctions.

Front 51

Paracrine signaling

Back 51

local regulator/mediator (type of hormone) released by cells into EC fluid in their neighborhood that act locally. involved in cell differentiation.

Front 52

Endocrine signaling

Back 52

hormones produced in endocrine glands and secreted in blood stream to various parts of body, Long distance hormonal signaling as hormones travel through bloodstream.

Front 53

Synaptic signaling

Back 53

. Neuronal: Signal is transmitted along axons to remote target cells
AP stimulates release of neurotransmitter that stimulates opening of gated-ion channels of neighboring cell (nerve or muscle) to transmit an AP
Results in transmition of AP along a nerve cell or stimulation of a muscle contraction

Front 54

kinase

Back 54

Ezymes that add phosphate groups. The action is reversed by protein phosphate enzymes.

Front 55

How does phosphorylation mess with proteins.

Back 55

it alters protein conformation to activate or repress it. I.e phosphorylated=active, dephosphorylated=inactive.

Front 56

Three stages in cell communication.

Back 56

1. reception- a chemical signal binds to a cellular protein, typically at the cell’s surface.
2.transduction- binding leads to a change in the receptor that triggers a series of changes along a signal-transduction pathway.
3. response- 
the transduced 
signal triggers 
a specific 
cellular 
activity.

Front 57

3 types of cell receptors.

Back 57

1.Chemically gated ion channels
2.Enzymatic receptors
3.G protein-coupled receptors (GPCR)

Front 58

Cells respond to a limited set of signals by responding to the SAME signal in DIFFERENT ways via:


Back 58

1. The various combination of receptors present on a given cell that can respond to extracellular cues.
2. The LEVEL of extracellular local signal present in the vicinity of a given cell (important in cell differentiation during development).
3. The various proteins within specific cell types

Front 59

The response of a particular cell to a signal depends on what?

Back 59

its particular collection of receptor proteins, relay proteins, and proteins needed to carry out the response.

Front 60

the same signal molecule can induce different responses in different target cells depending on

Back 60

Different receptors on cells, how the signal is interpreted internally.

Front 61

the same signal molecule can induce different responses in different target cells depending on

Back 61

Different receptors on cells, how the signal is interpreted internally.

Front 62

Intracellular signaling molecules

Back 62

a) small enough or hydrophobic enough to slip directly through PM
b) bind to receptors inside of the cell (generally t.f.)

Front 63

Where do cell surface signaling molecules bind to ?

Back 63

cell surface receptors

Front 64

Where do cell surface signaling molecules bind to ?

Back 64

cell surface receptors

Front 65

Three large families of cell surface receptors?

Back 65

ion-channel receptors, enzyme-linked receptors, G-Protein receptors.

Front 66

ligand-gated ion channels

Back 66

ion channel is closed, ligand binds, ion channel opens. ex. electrically excitable tissue (Nerves and Muscles).

Front 67

ligand-gated ion channels

Back 67

ion channel is closed, ligand binds, ion channel opens. ex. electrically excitable tissue (Nerves and Muscles).

Front 68

NADPH

Back 68

This is made in light reactions of photosynthesis.

Front 69

Calvin cycle

Back 69

Builds sugar from carbon dioxide, occurs in stroma.

Front 70

What are interphases 3 subphases?

Back 70

G1(synthesized proteins centered growth)=>Synthesis(S)(Chromsosomes are copied=>G2(Preperation for cell division,

Front 71

meiosis

Back 71

Takes place in gonads, yields four daughter cells, with half the chromosomes of parent. Reduces chromosomes 46 to 23. Fertilization fuses the gametes together and doubles the number of chromosome to 46 again.

Front 72

mitosis

Back 72

prophase, prometaphase, metaphase, anaphase, telophase.

Front 73

interphase G2

Back 73

DNA replicates, centrioles replicate, cell prepares for division.

Front 74

Prophase

Back 74

toot toot first stop we got chromosomes condensin and chromosomes appear as two sister chromatids held together at the centromere. Cytoskeleton is dissasembled: spindle begins to form. golgi and ER are dispersed. Nuclear envelope breaks down.

Front 75

Prometaphase

Back 75

chromosome attach to microtubules at the kinetochores. chromosomes move to equator of the cell.

Front 76

metaphase

Back 76

chromosomes are aligned at equator of the cell, called metaphase plate. chromosomes are under tension.

Front 77

anaphase

Back 77

proteins holding centromeres are degraded freeing individual chromosomes
Chromosomes are pulled to
opposite poles (anaphase A)
• Spindle poles move apart
(anaphase B)

Front 78

Telophase

Back 78

chromosomes are clustered at opposite poles and decondense, nuclear envelopes re-form around chromosomes, golgi complex and er re-form

Front 79

cytokinesis

Back 79

in animal cells, cleavage furrow forms to divide the cells, in plant cells, cell plate forms to divide the cell.

Front 80

Cell cycle control points are regulated by....

Back 80

CdKs

Front 81

Enzyme linked receptors

Back 81

1. Ligand binds to the receptor.
2. two receptors phosphorylate each other
3. Response proteins bind to phospho-
tyrosine on receptor. Receptor can
phosphorylate other response proteins

Front 82

G-protein-linked receptors

Back 82

Largest, Consists of a receptor protein on the cytoplasmic side, SEVEN alpha helices spanning the plasma membrane.

Front 83

If GDP is bound the G protein is inactive or active?

Back 83

inactive BITCH.

Front 84

misregulation of G-proteins results in..

Back 84

CANCER

Front 85

important things G-proteins do

Back 85

important role in embryonic development, cell cycle control and sensory systems.

Front 86

Ca2+ concentration in the cytosol vs outside the cell

Back 86

concentration in the cytosol is MUCH lower.