ch 2 cycling through life: metabolism

Question 1

metabolism

metabolism is the term for all the

Answer 1

chemical reactions our body must undergo to sustain life

Question 2

metabolism

proteins called enzymes control the

Answer 2

rate of these reactions that are of 2 types
* anabolic reactions
* catabolic reactions

Question 3

metabolism

anabolic reaction

Answer 3

require a source of energy to build up compounds that the body needs

Question 4

metabolism

catabolic reaction

Answer 4

break down larger molecules into smaller ones, releasing energy

tip: it can be catastrophic when things break down

Question 5

metabolism

the chemical alteration of molecules in the cell reffered to as

Answer 5

cellular metabolism

Question 6

metabolism

enzymes are biological catalysts that acclerate

Answer 6

chemical reactions without being changed

Question 7

metabolism

one way we can control the rate of our cellular metabolism is through the production of

Answer 7

enzymes or lack of production

Question 8

metabolism

what energy can cells use

Answer 8

adenosine triphosphate (ATP)

Question 9

metabolism

ATP’s energy is stored in the bonds that attach the

Answer 9

second and third phosphate groups

Question 10

metabolism

ATP is composed of

Answer 10

3 phosphate groups attached to adenosine
(a nitrogenous base of adenine paired with ribose)

Question 11

metabolism

when a cell needs energy what is the first step

Answer 11

• removes one or two phosphate groups
• releasing energy and converting ATP into either the
  two-phosphate molecule adenine diphosphate (ADP) or the one-phosphate molecule adenosine monophosphate (AMP)

Question 12

metabolism

when a cell needs energy what is the second step

Answer 12

later through additional metabolic reactions the second and third phosphate groups are reattached to adenosine reforming an ATP molecule until energy is needed again

ATP works like a rechargeable battery

Question 13

metabolism

most often we cycle through

Answer 13

ADP and ATP
AMP is only used in special scenarios

Question 14

energy from food

ATP is created via

Answer 14

cellular respiration
a process that occurs in and around the mitochondria of a cell

Question 15

energy from food

cellular respiration is a series of reactions that includes

Answer 15

• glycolysis
• the Krebs cycle
• electron transport cycle

Question 16

energy from food

cellular respiration starts with a

Answer 16

single molecule of glucose and produces 38 molecules of ATP

this process requires energy sources of its own which we gain from the foods we eat

Question 17

energy from food

the most efficient source (glucose) is gained from

Answer 17

• carbohydrate metabolism
• when this is used up we turn to the products of lipid metabolism
• finally to the products protein metabolism

Question 18

energy from food

each energy source enters the cellular respiration process at

Answer 18

different points

Question 19

carbohydrate metabolism

the metabolism of all carbohydrates leads to the eventual production of

Answer 19

glucose

Question 20

carbohydrate metabolism

the glucose is then utilized in the first phase of cellular respiration

Answer 20

glycolysis

Question 21

lipid metabolism

lipids contain about 99% of the body’s stored

Answer 21

energy and can be digested at mealtime

Question 22

lipid metabolism

where are lipids stored in the body

Answer 22

instead of fats going straight to the hips it is more inclined to be stored in adipose tissue (generally identified as body fat)

Question 23

lipid metabolism

when the body is ready to metabiliza lipids an enzyme called

Answer 23

lipase splits them into their monomer units:
* glycerol
* fatty acid chains

Question 24

lipid metabolism

glycerol

Answer 24

• has 3 carbons
• then converted into pyruvate

Question 25

lipid metabolism

acetyl CoA

Answer 25

• a different series of reactions of catabolic reactions breaks apart 2 carbon atoms from the end of a fatty acid chain to form this
• then enters the Krebs Cycle to produce ATP
• those reactions to continue to strip 2 carbon atoms at a time until the entire fatty acid chain is converted into acetyl CoA molecules

Question 26

protein metabolism

protein metabolism focuses on producing the

Answer 26

amino acids needed for synthesis of protein molecules within the body

Question 27

protein metabolism

but like the lipids the amino acids can be converted into

Answer 27

• pyruvate
• acetyl CoA

Question 28

protein metabolism

additionally protein metabolism generates energy molecules such as

Answer 28

• NADH and FADH2
• that power the final step of cellular respiration–the electron transport chain