lecture exam 2 Flashcards
what is metabolism
all chemical reactions in a cell
What’s Endergonic reactions?
also know as Anabolism; forms larger macromolecules from smaller molecules; requires energy input
what are the two types of chemical reactions?
catabolism and anabolism
what are exergonic reactions?
also known as catabolism; breaks the bonds of larger molecules forming smaller molecules
molecules that carry the electrons removed from glucose are called…
electron carriers
not carrying electrons; is the oxidized form of the molecule
NAD+ and FAD
is carrying electrons; is the reduced form of the molecules
NADH and FADH2
the energy currency of the cell; constant cycle in active cells
ATP
what are the 3 part molecules of ATP
adenine- a nitrogenous base
ribose- a 5-carbon sugar
3 phosphate groups
what is phosphorylation
when the 3rd phosphate group is put on ADP and it is accomplished with a kinase enzyme
ADP becomes ATP
when is ATP made in a cell?
a cell must always constantly make ATP and is made during cellular respiration. input energy comes from the oxidation (breakdown) of glucose
what is dephosphorylation?
when the 3rd phosphate group is removed from ATP. ATP becomes ADP. energy is released
what are enzymes?
biological catalysts that increase the rate of chemical reaction by lowering the energy of activation (the resistance to a reaction)
the chemical reactants to which an enzyme binds are called…
substrates
the location within the enzyme where the substrate binds is called the enzymes’s…
active site.
each enzyme binds to one specific substrate
name 7 enzyme characteristics
- biological catalyst
- protein in structure
- special three dimenional shape
- sensitive to changes in pH, temp, ionic concentration leads to denaturation
- reusable
- very specific
- usually has ‘ase’ ending
what is labile?
chemically unstable enzymes
what is denaturation?
weak bonds that maintain the shape of the protein are broken
what are 2 enzyme helpers?
cofactor and coenzyme
describe cofactor
smaller, inorganic
usually a metallic ion: copper, zinc, iron
are near or within the active site and participates directly in the chemical reaction
describe coenzyme
larger, organic
usually part of a vitamin
removes functional groups from a substrate; acts as a carrier
Ex: NADH+, FAD
what does enzyme regulation do?
enzymes can be regulated to promote or reduce their activity
what is competitive inhibitor?
a molecule similar enough to a substrate that competes with the substrate for the binding at the active site. concentration of both must be equal
ex. sulfa drugs kill bacteria by binding with the enzyme that makes folic acid
what is a noncompetitive or allosteric inhibitor
binds the enzyme at the allosteric site which is a location other than the active site
what are 3 catabolic pathways that convert glucose to CO2 and gives off energy?
aerobic respiration, anaerobic respiration and fermentation
what is anaerobic respiration
includes: glycolysis, krebs cycle, ETC
Energy produced= 5-36 ATPs
final electron acceptor:
nitrate (NO3-)
nitrite (NO2-)
sulfate (SO4^-2)
ferrous ion (FE+3)
carbonate (CO3-)
carbon dioxide (CO2)
NOT OXYGEN
What is fermentation?
uses glycolysis only (incomplete oxidation)
glucose–>pyruvic acid–>another molecule
the energy produced a small amount of ATP, 2-4 ATP
NO OXYGEN
production of ethyl alcohol by yeasts acting on glucose
formation of acid, gas, & other products by the action of various bacteria on pyruvic acid
what is aerobic respiration?
glycolysis, kreb’s cycle, ETC
oxygen is needed as the final electron acceptor
yields 38 ATPs total
what is the overall equation for aerobic respiration?
C6H12O6 + 6O2 + 38ADP + 38P —> 6CO2 + 6H2O + 38ATP
describe the pathway for glycolysis in aerobic respiration and where does it occur
1.) glucose is oxidized and split into 2 molecules of pyruvic acid and generates 2 ATP and 2 NADH
2.) occurs in the cytoplasm of prokaryotic/eukaryotic cell
3.) involves a energy investment phase and energy payoff phase
4.) NO OXYGEN NEEDED
Describe the pathway of the Krebs cycle in aerobic respiration and where does it occur
1.) processes 2 pyruvic acids and generates 6CO2, 2ATP, 8 NADH & 2 FADH2
2.) in cytoplasm of prokaryotic cell/mitochondrial matrix of eukaryotic cell
3.) bridge reaction (glycolysis) must occur first. 2 pyruvic acids (from glycolysis) converted to 2 Acetyl CoA—> enter krebs cycle
4.) 1 acetyl CoA is needed for each turn of wheel
5.) NO OXYGEN NEEDED
describe the ETC pathway in aerobic respiration and where does it occur
1.) accepts electrons from NADH and FADH; generates energy through sequential redox reactions called oxidative phosphorylation and generates 34 ATP
2.) In cell membrane of prokaryotic/inner mitochondrial membrane of eukaryotic cells
what are the exchange rate for coenzyme in ETC
1 NADH ields = 3 ATP
1 FADH2 yields = 2 ATP
what is photophosphorylation?
ATP is formed using the energy of sunlight (photosynthetic organisms)
what is oxidative phosphorylation?
series of redox reactions occurring during respiratory pathway (occurs in ETC)
What is substrate-level phosphorylation?
transfer of phosphate group from a phosphorylated compound (substrate) directly to ADP (occurs during glycolysis and Krebs cycle)
the phosphorylation of ADP to mKE atp is accomplished with a kinase enzyme
what are 3 different ways ATP can be formed?
substrate-level phosphorylation
oxidative phosphorylation
photophosphorylation
what is the terminal step?
oxygen accepts 2 electrons from ETC & picks up 2 hydrogen ions from the solution to form a molecule of water. oxygen is the final electron acceptor
what is chemiosmosis
as electrons transport carriers move electrons, they actively pump hydrogen ions across the membrane setting a gradient of hydrogen ions- proton motive force. the hydrogen ions. Hydrogen ions diffuse back through the ATP synthase complex causing it to rotate, causing a 3-D change resulting in the production of ATP
In what circumstances will aerobic respiration not be possible
- cell lacks a sufficient amount of oxygen
- cell lacks genes encoding enzymes to minimize the damaging effects of dangerous oxygen radicals produced during aerobic respiration, such as hydrogen peroxide or superoxide
- cell lacks genes encoding an appropriate cytochrome oxidase for transferring electrons to oxygen at the end of ETC
what is genetics? name 7 things it involves
the study of the inheritance or heredity of living things. this involves:
*transmission of biological properties (traits) from parent to offspring
*expression and variation of those traits
*structure and function of genetic material
*How this material changes through time = EVOLUTION
*important molecules are DNA, RNA, and proteins
*DNA and RNA carry information
*Proteins carry out most cellular functions and are built using the information in DNA and RNA
what is vertical gene transmission?
the transfer of information from parent to daughter cells. accomplished by DNA replication
what is the function of DNA?
Stores the information needed to build and control the cell
what is a genome?
sum of total of genetic material of a cell
what is the genome of all cells?
DNA
what is the genome of viruses?
RNA or DNA
DNA complexed with _____ constitutes the genetic material as chromosomes
priotein
bacterial chromosomes are single circular loop found in the cytoplasm in a region called the….
nucleoid
eukaryotic chromosomes are multiple and linear found in the…
nucleus
what is the fundamental unit of heredity responsible for a given trait
gene; chromosome is subdivided into genes
what does a gene do?
provides information for a certain cell function
segment of DNA that contains the necessary code to make a protein, enzymes, or RNA molecules
the full collection of genes that a cell contains within its genome is called the
genotype
the expression of a set of genes that determines the cell observable characteristics is called
phenotype
what are two types of genes?
constitutive and nonconstitutive genes