Chapter 1

Question 1

biochemistry

Answer 1

study of living organisms at the molecular level

Question 2

eukaryotes

Answer 2

contain a membrane-enclosed nucleus

Question 3

living cells require

Answer 3

• barrier that separates it from its environment
• interior that is chemically distinct from the surroundings

Question 4

cellular membranes

Answer 4

two layers of lipids whose hydrophobic tails interact on the interior and whose hydrophilic heads interact with the environment

Question 5

plasma membrane

Answer 5

selectively permeable to fuels, building blocks and signal molecules that must enter the cell

Question 6

cytoplasm

Answer 6

• material that comprises the cell interior
• many biochemical processes including glucose metabolism, fatty acid synthesis, and protein synthesis

Question 7

cytoskeleton

Answer 7

gives the cell its structure and serves as a system of “molecular highways” for materials transport throughout the cell

Question 8

nucleus

Answer 8

information center of the cell and the location of the organism’s genome

Question 9

mitochondria

Answer 9

ATP generation

Question 10

endoplasmic reticulum

Answer 10

membranous sacs surrounding the nucleus

Question 11

smooth ER

Answer 11

processes chemicals originating outside the cell, such as drugs

Question 12

rough ER

Answer 12

ribosomes for protein manufacture are attached

Question 13

golgi complex

Answer 13

stacked membranes that receive transport vesicles from the rough ER and processes the proteins for secretion of delivery to the plasma membrane

Question 14

secretory vesicles

Answer 14

carry cargo of mature proteins to the plasma membrane

Question 15

lysosome

Answer 15

digests material brought into the cell by endocytosis

Question 16

chloroplast

Answer 16

found only in plant cells and is the site of photosynthesis

Question 17

vacuoles

Answer 17

store water, ions, and various nutrients

Question 18

cell wall

Answer 18

constructed from cellulose to form a protective wall around the cell

Question 19

elements of life

Answer 19

hydrogen (63%), carbon (9%), and oxygen (25%)

Question 20

why hydrogen and oxygen

Answer 20

H20 is matrix of life, polar molecule allowing it to self-interact and form weak bonds

Question 21

why carbon

Answer 21

forms 4 covalent bond, C-C bonds release a lot of energy

Question 22

stereoisomers

Answer 22

same atom connectivities but differ in arrangement

Question 23

chiral

Answer 23

not superimposable on mirror images

Question 24

enantiomers

Answer 24

a molecule and its non-superimposable mirror image

Question 25

proteins

Answer 25

20 different monomer building blocks (amino acids)

Question 26

N-terminus

Answer 26

(beginning) free amine (NH2) group

Question 27

C-terminus

Answer 27

(end) free carboxyl (COOH) group

Question 28

proteins are highly versatile

Answer 28

regulation, storage, motion, transport, defense, and structure

Question 29

catalysts

Answer 29

agents that enhance the rate of a chemical reaction

Question 30

protein catalysts

Answer 30

enzymes

Question 31

nucleotide

Answer 31

five-carbon sugar attached to heterocyclic ring and a phosphoryl group

Question 32

nucleotides are joined by

Answer 32

phosphodiester bonds to form linear molecules

Question 33

DNA

Answer 33

stores genetic information

Question 34

RNA

Answer 34

transfers information

Question 35

carbohydrates

Answer 35

3-9 carbon atoms and simple sugars

Question 36

carbohydrates are

Answer 36

fuel sources, signaling molecules

Question 37

lipids

Answer 37

water-insoluble organic molecules, form barriers to protect the cell and its organelles

Question 38

thermodynamics

Answer 38

system (any part under study) surroundings (everything else)

Question 39

open systems

Answer 39

exchange matter and energy

Question 40

closed systems

Answer 40

exchange matter

Question 41

first law of thermodynamics

Answer 41

energy can be converted but neither created nor destroyed

Question 42

Enthalpy (ΔH)

Answer 42

heat evolved in a reaction at constant pressure

Question 43

Entropy (S)

Answer 43

degree of randomness or disorder in a system

Question 44

Gibbs Free Energy

Answer 44

ΔG = ΔH - TΔS

Question 45

exergonic

Answer 45

negative ΔG (spontaneous)

Question 46

endergonic

Answer 46

positive ΔG (nonspontaneous_

Question 47

free enegry

Answer 47

energy is capable of doing useful work

Question 48

central dogma

Answer 48

genetic information is stored in DNA and it can be replicated, and passed through an RNA intermediate before being expressed as a protein

Question 49

replication

Answer 49

DNA acts as a template for the synthesis of new DNA

Question 50

DNA polymerase

Answer 50

catalyze the replication process and duplicate the genome

Question 51

transcription

Answer 51

DNA is used as a template for the synthesis of an RNA

Question 52

RNA polymerase

Answer 52

catalyzes transcription

Question 53

translation

Answer 53

messenger RNA copy is interpreted and used to drive the synthesis of protein