Test 2 - Ch's 6,7,8

Question 1

Define metabolism.

Answer 1

Sum of all the chemical reactions in a cell.

Question 2

What is the difference between catabolic and anabolic reactions?

Answer 2

Catabolic reactions involve converting energy from the environment into a usable form (ATP), while anabolic reactions use the energy from the ATP produced to do work.

Question 3

What are the two types of reactions in metabolism?

Answer 3

Catabolic and anabolic.

Question 4

Why study microbial metabolism?

Answer 4

Look for differences between their metabolism and ours- gives us drug targets that won’t affect our cells.

Question 5

Define energy.

Answer 5

Ability to do work.

Question 6

What are the two kinds of energy? Define them. Can energy be destroyed?

Answer 6

Kinetic - energy of motion
Potential - stored energy
First Law of Thermodynamics- energy is neither created nor destroyed, only transformed.

Question 7

How is energy stored in living things? How do we release this energy?

Answer 7

Chemical bonds; in order to release energy chemical bonds must be broken.

Question 8

Name the two types of reactions involved in chemical reactions and define them.

Answer 8

Exergonic reactions - have more energy stored in their reactants then in the products.
Endergonic reactions - have more energy stored in their products then in the reactants.

Question 9

In living things, energy is stored and released through chemical bonds. What reactions release energy and which ones store it?

Answer 9

Exergonic reactions release energy while endergonic reactions store it.

Question 10

What are the three kinds of metabolic pathways and define them.

Answer 10

Linear - one starting molecule makes one end product
Branched - one starting makes more than one different end product
Cyclical - starting molecule is regenerated at the end of the pathway

Question 11

What are the components of metabolic pathways?

Answer 11

ATP, energy source, e- donor, e- carriers, and enzymes.

Question 12

Why is ATP significant to living things?

Answer 12

Adenosine Triphosphate is the usable energy molecule of cells.

Question 13

Describe how to get energy out of ATP and how to regenerate ATP.

Answer 13

One of the three phosphate groups attached to ATP must break off (breaking the chem bond), which releases energy. ATP is then ADP, but can be used to create another ATP molecule by adding a phosphate group (phosphorylation).

Question 14

Define phosphorylation.

Answer 14

When a phosphate group is added to ADP to create ATP, requires energy.

Question 15

What are the three types of phosphorylation?

Answer 15

Substrate level phosphorylation, Oxidative ph., and photophosphorylation.

Question 16

What are the three e- carriers?

Answer 16

NAD+, FAD+, and NADP+

Question 17

What is fermentation?

Answer 17

The incomplete breakdown of a carbohydrate.

Question 18

What are the four parts of the central metabolic pathways?

Answer 18

Glycolysis, Transition Step, Kreb’s Cycle, and Electron Transport Phosphorylation.

Question 19

What is the net gain of ATP from CMP?

Answer 19

32-34 ATP

Question 20

What are the two parts of fermentation?

Answer 20

Glycolysis (exactly as in CMP), and end product formation.

Question 21

What are some of the common end products of fermentation?

Answer 21

Lactic acid, ethanol, propionic acid, and 2,3 butanediol and acetoin.

Question 22

Pyruvate can be converted into lactic acid by various organisms, but the one found in yogurt is _____ bacteria.

Answer 22

Lactobacillus

Question 23

What are two places to find Lactobacillus?

Answer 23

Yogurt and the human vagina.

Question 24

Yeast are able to convert pyruvate from glycolysis in fermentation to ______. CO2 is the waste product.

Answer 24

Ethanol - drinkable alcohol.

Question 25

What is the name of the organism that produces Propionic Acid in end product formation?

Answer 25

Propionibacterium

Question 26

Where can you find Propionibacterium? What can they produce in end product formation?

Answer 26

Swiss cheese, propionic acid.

Question 27

Some types of Coliform bacteria produce ______ as an end product in fermentation. Where can you find this bacteria?

Answer 27

2,3 butanediol and acetoin. Coliform means intestinal, so tests are done when fecal contamination of food is tested.

Question 28

Define replisome.

Answer 28

Group of enzymes that work in series.

Question 29

What is the job of tRNA?

Answer 29

To carry a certain amino acid to the rRNA and adds them to the chain.

Question 30

What is the job of Helicase?

Answer 30

To unzip DNA and to create a replication fork.

Question 31

What does Primase do?

Answer 31

Primase creates a small piece of RNA that acts as a primer to attach to the 3’ end of each unzipped DNA strand. Helps DNA polymerase by giving it a place to attach.

Question 32

In what direction does DNA polymerase read DNA?

Answer 32

3’ -> 5’

Question 33

What does DNA polymerase do?

Answer 33

Creates a new strand of DNA that matches the template strand by complementary base pairing and replaces primer with deoxynucleotides.

Question 34

In what direction does DNA polymerase create DNA?

Answer 34

Can only make the new strand 5’ to 3’.

Question 35

What is the job of DNA Ligase?

Answer 35

Enzyme that joins the Okazaki fragments together into one piece.

Question 36

Define gene.

Answer 36

Section of DNA that has the instructions for making one protein.

Question 37

Define gene expression.

Answer 37

Using the instructions form DNA to make protein. Two parts are transcription and translation.

Question 38

Tell the difference between monocistronic and polycistronic.

Answer 38

Monocistronic - piece of mRNA carries the instructions for only one gene. (Humans)
Polycistronic - piece of mRNA carries the instructions for more than one gene. (Bacteria)

Question 39

Define sigma factor.

Answer 39

Portion of the RNA polymerase that recognizes and binds to the promoter. Falls off after transcription begins.

Question 40

What are the two strands of DNA called, once unzipped, involving transcription? Which one is used as the template strand for mRNA? Why?

Answer 40

The two strands are + (sense) and - (missense), and the one used in transcription as a template is the missense strand because it ensures that the mRNA is made in a sense form.

Question 41

Distinguish the promoter from the terminator in transcription.

Answer 41

Promoter - segment of DNA upstream of the gene

Terminator - segment downstream of the gene

Question 42

What are the three steps called in both transcription and translation? Do they mean the same things?

Answer 42

Initiation, Elongation, and Termination. Although they have the same names, the steps for both processes are different.

Question 43

What additional stuff happens in gene expression for eukaryotes that doesn’t happen in prokaryotes?

Answer 43

Euk’s have post transcriptional modifications (cap and tail to mRNA), splicing to remove introns, and the joining of exons.

Question 44

Why should prokaryotes regulate gene expression?

Answer 44

They need to control gene expression based on the environment they are in, like why waste energy to make a molecule that they could get in the environment.

Question 45

What are the two types of regulatory proteins involved in prokaryotic gene expression?

Answer 45

Repressors and Activators.

Question 46

What are repressors and what do they do?

Reversible.

Answer 46

They are regulatory proteins that block transcription (turns it off) by blocking RNA polymerase. These are allosteric molecules, meaning they can change shape to become active or inactive.

Question 47

What are activators and what do they do?

Reversible.

Answer 47

Regulatory proteins that helps transcriptions occur (turns it on), usually in instances where RNA polymerase does not bind to the promoter well. These proteins help RNA polymerase bind to the promoter and are allosteric molecules (change shape to become active or inactive).