Chapter 4 - The Energy of Life

Question 1

Define cell transport

Answer 1

movement of materials across cell membranes

Question 2

List 2 differences between facilitated diffusion and active transport

Answer 2

Active transport moves small molecules from a low concentration to a high concentration; energy and carrier proteins are required

Facilitated diffusion moves small substances from a high concentration to a low concentration; energy is not required; carrier proteins are required.

Question 3

How is active transport and facilitated diffusion similar?

Answer 3

Both active transport and facilitated diffusion move molecules and use carrier proteins to move the molecules

Question 4

List the 3 types of passive transport

Answer 4

Osmosis, diffusion, facilitated transport of facilitated diffusion

Question 5

Define diffusion

Answer 5

The movement of a substance from a high concentration to a low concentration; Energy is not required

Question 6

Define osmosis

Answer 6

Water moves from a high concentration to a low concentration; Energy is not required

Question 7

What is the difference between a hypotonic solution and a hypertonic solution?

Answer 7

Hypotonic – low concentration; water enters the cell, cell may swell or burst

Hypertonic – high concentration; water leaves the cell, cell may shrink

Question 8

Define isotonic

Answer 8

Isotonic – same concentration; cell retains its shape

Question 9

What is the effect of a hypotonic solution on a cell?

Answer 9

Hypotonic – low concentration; water enters the cell, cell may swell or burst

Question 10

What is the effect of a hypertonic solution on a cell?

Answer 10

Hypertonic – high concentration; water leaves the cell, cell may shrink

Question 11

What is the difference between exocytosis and endocytosis?

Answer 11

Exocytosis – vesicles fuse with the plasma membrane releasing their contents from the cell

Endocytosis – large molecules, cells, or cell fragments are brought into the cell in a vesicle

Question 12

List some differences between phagocytosis and pinocytosis?

Answer 12

Phagocytosis – pseudopods (moving cytoplasmic extensions) surrounds large molecules, fragments of cells, or small cells, entrapping them in a vesicle in a cell

Pinocytosis – invagination of the plasma membrane entraps a large molecule in a vesicle

Question 13

Define metabolism

Answer 13

Sum of all energy and chemical changes in a call

Question 14

Define energy

Answer 14

The ability to do work

Question 15

What is the difference between potential and kinetic energy?

Answer 15

Potential – “stored energy”; energy available to do work

Kinetic – energy of motion

Question 16

List the 5 types of energy

Answer 16

Light (radiant), heat (thermal), electricity, chemical, mechanical

Question 17

Define calorie

Answer 17

a unit of heat

Question 18

How are calories measured?

Answer 18

7.3 kcal over mole

the amount of heat required to raise 1 gram or I milliliter of water 1 degree Celsius

Question 19

What is the relationship between a kilocalorie and a calorie?

Answer 19

A kilocalorie is 1000 calories

Question 20

Define chemical change

Answer 20

atoms rearrange in a molecule to form a new molecule

Question 21

What are the two divisions of metabolism?

Answer 21

Catabolism and anabolism

Question 22

What is the difference between catabolism and anabolism?

Answer 22

Catabolism – degrade; decompose (break large molecules into small molecules)

Anabolism – compose; synthesize (combine small molecules together to form a large molecule

Question 23

Identify examples of catabolism and anabolism

Answer 23

Catabolism – AB yields A + B

Anabolism – A + B yields AB

Question 24

What are electron carriers?

Answer 24

Molecules that carry 2 electrons and either 1 or 2 hydrogen ions

Question 25

List the 3 types of electron carriers

Answer 25

Nicotinamide, adenine, dinucleotide NAD – not carrying the 2 electrons or the single hydrogen ions NADH – is carrying the 2 electrons and the single hydrogen ion Nicotinamide, adenine, dinucleotide, Phosphide NADP – not carrying the 2 electrons or the single hydrogen ions NADPH – is carrying the 2 electrons and the single hydrogen ion Flavin, adenine, dinucleotide FAD – not carrying the 2 electrons or the 2 hydrogen ions FADH2 – is carrying the 2 electrons and the 2 hydrogen ions

Question 26

What is the difference between the oxidized and reduced form of each electron carrier?

Answer 26

Oxidization – loss of electrons from a molecule, atom, or ion. Reduction – gain electrons

Question 27

List 2 differences between ADP and ATP

Answer 27

ATP is made up of Adenine, ribose, and 3 phosphates; has more energy ADP is made up of Adenine, ribose, and 2 phosphates

Question 28

What is the chemical formula for ribose?

Answer 28

C5 H10 O5

Question 29

What are the differences between substrate level phosphorylation and chemiosmosis?

Answer 29

Substrate level phosphorylation – an intermediate called the substrate transfers the energy and its phosphate to ADP to form ATP Chemiosmosis – electrons drive the movement of protons across ATP synthase in the membrane; the energy derived from the movement of the protons is enough to combine APD & the phosphate (PO3) to form ATP

Question 30

What is the function of ATP synthase?

Answer 30

An important enzyme that creates the energy storage molecule ATP

Question 31

What is an Enzyme?

Answer 31

speeds up chemical reactions

Question 32

List 4 characteristics of enzymes

Answer 32

1. Organic molecules made of protein or ribonucleic acid (RNA) 2. Catalyst – substance that speeds up a chemical reaction but is not changed permanently in the chemical reaction 3. Lowering the activation energy – energy required to disassemble the atoms in a molecule so they can recombine to form a new molecule 4. Highly specific – will only catalyze certain chemical reactions Enzyme – substrate Catalase – hydrogen peroxide Amylase – starch DNA Polymer – Nucleotide

Question 33

What is the relationship between the substrate and the active site of an enzyme?

Answer 33

The substrate bonds to the enzyme at the active site

Question 34

Define active site

Answer 34

place on the enzyme where the substrate bonds

Question 35

Define substrate

Answer 35

molecule acted upon by the enzyme

Question 36

What is the fate of E and S in the enzymatic equation, E + S -> ES -> E + P

Answer 36

E = enzyme goes in and comes out an enzyme S = substrate goes in and becomes the product

Question 37

Identify the parts of an enzymatic reaction in a chemical reaction that involves an enzyme

Answer 37

Enzyme, substrate, enzyme substrate complex, and product | E + S -> ES -> E + P

Question 38

Define activation energy

Answer 38

energy required to disassemble the atoms in a molecule so they can recombine to form a new molecule

Question 39

How are enzymes denoted?

Answer 39

Most denoted by “ase”

Question 40

Explain why enzymes are characterized as highly specific

Answer 40

They will only catalyze certain chemical reactions Enzyme – substrate Catalase – hydrogen peroxide Amylase – starch DNA Polymer – Nucleotide

Question 41

What is the electromagnetic spectrum?

Answer 41

A series of frequencies of radiation; cosmic, gamma, x-rays, etc.

Question 42

Define photon

Answer 42

bundle of light energy

Question 43

What is the difference between the ground state and the excited state of an atom?

Answer 43

Ground state – electrons have less kinetic energy Excited state – electrons have more kinetic energy

Question 44

Describe chlorophyll

Answer 44

green pigment found in algae, plants, blue green algae that absorb light during photosynthesis

Question 45

Magnesium Atom

Answer 45

12 protons; 12 neutrons; 12 electrons

Question 46

Describe the function of 4 membrane proteins?

Answer 46

Transport proteins – transport proteins embedded in the phospholipid bilayer create passageways through which ions, glucose, and other polar substances pass into or out of the cell Enzymes – speeds up a chemical reaction but is not permanently changed in the chemical reaction Recognition proteins – Carbohydrates attached to cell surface proteins serve as “name tags” that help the body recognize its own cells. Adhesion proteins – These membrane proteins enable cells to stick to one another Receptor proteins – bind to molecules outside the cell and trigger an internal response

Question 47

Lipid

Answer 47

contains carbon, hydrogen, & oxygen with hydrogen and oxygen in a ratio that exceeds 2:1 Fatty Acid - contains carboxyl group, methyl group, and hydrocarbon chain Tryglyceride - glycerol molecule and 3 fatty acids

Question 48

Protein

Answer 48

molecule that contain carbon, hydrogen, oxygen, nitrogen, and sulfur; basic unit is an amino acid Amino acid - all have a terminal hydrogen, carboxyl group, amino group, and the alpha carbon. They differ from each other due to the R Group