Intro to Metabolism

Question 1

what are metabolites?

Answer 1

small intermediates in degradation or biosynthesis of biopolymers

Question 2

what are anabolic reactions?

Answer 2

reactions that synthesise molecules

Question 3

what are catabolic reactions?

Answer 3

reactions thar degrade molecules

Question 4

what is catabolism?

Answer 4

degradation of large molecules to liberate smaller molecules and energy

Question 5

what are amphibole reactions?

Answer 5

reactions involving catabolism and anabolism

Question 6

what is a metabolic pathway?

Answer 6

a series of reactions where one product of the reaction becomes a substrate for another

Question 7

what is an example of a linear reaction?

Answer 7

biosynthesis of serine

Question 8

what is an example of a circular reaction?

Answer 8

citric cycle

Question 9

what is a branch point of a metabolic pathway?

Answer 9

a point at which intermediates may enter or leave

Question 10

in what conditions do cellular reactions usually occur at?

Answer 10

moderate temperature and pressure, low reactant concentrations and close to neutral pH

Question 11

what is energy flow?

Answer 11

energy donors and acceptors carrying discrete packets of energy from one step to another

Question 12

in what ways is metabolism controlled?

Answer 12

feedback inhibition and feedforward activation

Question 13

what is feedback inhibition?

Answer 13

when the output of a process is used as an input to control the behaviour of the process itself

Question 14

what is feedforward activation?

Answer 14

an early product in the pathway activates and catalyses future reactions down the pathway

Question 15

where are hydrogen atoms/electrons used in reactions?

Answer 15

in oxidative phosphorylation and in reduction reactions in biosynthesis

Question 16

where is ATP produced?

Answer 16

substrate level phosphorylation

Question 17

what are the products of catabolism?

Answer 17

hydrogen atoms/electrons, ATP, CO2 and nitrogen

Question 18

what kind of reaction is catabolism?

Answer 18

oxidative that releases energy

Question 19

what kind of reaction is anabolism?

Answer 19

reductive that requires energy

Question 20

what is a redox reaction?

Answer 20

those in which electrons are transferred between species

Question 21

what is compartmentation?

Answer 21

the separation of metabolic processes that together constitute a metabolic cycle

Question 22

how is compartmentation shown for example?

Answer 22

when some metabolic pathways are localised to particular parts of the cell e.g. ETC in the cell membrane

Question 23

what are the different types of nucleoside triphosphate?

Answer 23

ATP, GTP, CTP, UTP

Question 24

what are the different ways in which phosphoanhydride bridges contribute to energy release?

Answer 24

reduced electrostatic repulsion, solution effects, resonance stabilisation, and that they are energy rich systems

Question 25

why is the energy produced in one reaction usually coupled with another?

Answer 25

because without coupling, the first reaction would not occur spontaneously

Question 26

how can a substrate such as ATP become activated?

Answer 26

transfer of a phosphorylase group or a nucleotide group