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Flashcards in Unit 5 Deck (45):
1

What does ATP stand for

Adenosine triphosphate

2

What type of reaction is the synthesis of ATP

Condensation as it produces water

3

What type of reaction is the metabolism of ATP

Hydrolysis as it uses water to split the molecule, removing the terminal phosphate.

4

What is ATP used for in the cell?

Active transport (mineral uptake in root hair cells, absorption of AA's in PCT of kidney)
Anabolic reactions (protein synthesis from AA's, building polysaccharides from monosaccharides)
Mechanical work (muscle action, ciliary action, spindle action in nuclear division)

5

What are the stages of the biochemistry of respiration?

1- Glycolysis
2- Link reaction
3- Krebs cycle
4- ETC

6

Glycolysis

Glucose is converted into fructose bisphosphate, during this two molecules of ATP are converted into two molecules of ADP.
Then the fructose bisphosphate is converted into two molecules of triose phosphate. Each molecule of triose phosphate is converted into a molecule of pyruvate- during this two molecules of ATP are produced and a molecule of NADP is produced (with help from dehydrogenase enzymes catalysing dehydrogenation) per molecule of pyruvate produced.

7

Link reaction

Each molecule of pyruvate undergoes oxidative decarboxylation (releasing a molecule of CO2 and NADH) to produce a molecule of acetate, which reacts with coenzyme A (CoA) to produce acetyl CoA.

8

Krebs cycle

Acetyl CoA reacts with oxaloacetate to produce a molecule of citrate, which undergoes decarboxylation and dehydrogenation to produce a molecule of NADH and oxoglutarate, which under goes triple decarboxylation (making two NADHs and a FADH2) and substrate level phosphorylation to produce ATP and an oxaloacetate molecule. Cycle turns twice per glucose molecule.

9

Electron transport chain

Carriers:
!= ATP produced by oxidative phosphorylation
For NADH
NAD-NADH-!-flavoprotein-r.flavoprotein-CoQ-r.CoQ-!-cytochromes-!-r.cytochromes-cytochrome oxidase producing water

For FADH2
CoQ-r.CoQ-!-cytochromes-!-r.cytochromes-cytochrome oxidase producing water

10

How many molecules of ATP are produced per molecule of glucose

38
2 from glycolysis, 2 from Krebs and 34 from ETC

11

How are leaves adapted for ps

Palisade mesophyll cells directly under upper surface of the leaf- densely packed with chloroplasts maximising light absorption in chloroplasts
Spongy mesophyll cells lie underneath the palisade mesophyll which contain numerous air spaces forming a continuous pathway with the stomata facilitating gas exchange

12

What are the pigments in a chloroplast?

Chlorophyll-a, chlorophyll-b and carotene

13

Light harvesting

There are antenna complexes in the membrane of the thylakoids in the chloroplasts. Incident light reaches the antenna complex and the energy is funnelled toward the chlorophyll-a molecule in the reaction centre via accessory pigments by resonance transfer.
Energy causes the photo activation and emission of an electron from the primary pigment.

14

Light dependant reaction

The photolysis of water produces oxygen (waste) and protons. The electron released from the photosystem/antenna complex is accepted by an electron acceptor and then travels down an ETC by a series of redox reactions along cytochromes forming the carriers in the chain itself in progressively lower energy levels. As the electron loses energy while travelling down the ETC at a certain point enough energy is released to cause the photophosphorylation of adenosine diphosphate to form adenosine triphosphate. The electron the enters photosystem 1 and is emitted and subsequently accepted by an electron acceptor. The electrons combine with the protons to form hydrogen which combines with NADP to form NADPH

15

DNA

Deoxyribonucleic acid

16

RNA

Ribonucleic acid

17

Gene

A length of DNA that codes for a particular polypeptide

18

Description of DNA

Non overlapping each triplet read once
Degenerate each AA may be produced from more than one triplet
Three base

19

Why can't DNA be used for protecting synthesis directly?

It is too large to leave the nucleus
It is safer to keep it in the nucleus where it is better protective from damage as it the molecule of inheritance so it's important to protect
DNA can produce several copies of RNA allowing for more proteins to be produced simultaneously

20

Transcription

The two strands of DNA are separated by DNA helicase using energy from ATP
The RNA polymerase attaches near the beginning of the gene to be transcribed
The template strand is used for mRNA production. The RNA polymerase moves along the template strand attaching complementary ribonucleotides by the process of complementary base pairing
As the RNA polymerase moves along the DNA it reforms behind it- when the RNA polymerase reaches the end of the gene it releases the newly formed mRNA

21

Introns

Non coding regions of a gene

22

Exons

Coding regions of a gene

23

Translation

The mRNA contains a series of base triplets called codons. The ribosomes contain two sites, the aminoacyl site at and the peptidyl site, where the peptide bonds between adjacent amino acids are formed, this requires ATP. The first two codons enter the ribosome. The starting codon is AUG at the peptidyl site and the second at the A site. Then tRNA molecules carry complementary anticodons with corresponding amino acids and join with the complementary codon at the p site, then at the a site. tRNA is a single strand of DNA shaped like a clover with a specific anticodon and an amino acid. Then the ribosome moves along the mRNA by one codon, and the next codon enters at the A site. The tRNA is released and will travel to the cytoplasm to get another amino acid. This repeats until the ribosome reaches a stop codon.

24

Epigenetics

The study of the changes in gene expression that do not involve changes to the base sequence of the DNA. Caused by changes in the cell environment so that some genes are on and others are off.

25

Monohybrid inheritance

The inheritance at one gene locus, single charcteristic

26

Gene

Length of DNA that codes for a particular trait

27

Genetic Locus

The position of a gene on the chromosome

28

Allele

An alternative form of a gene

29

Dominant allele

An allele that has its instruction followed in the heterozygous condition

30

Recessive allele

An allele that has its instruction followed in the homozygous condition

31

Hereditiy

The transfer of genetic factors from one generation to the next.

32

Mendel's First Law

When any individual produced gametes, the alleles separate so that each gamete receives only one allele. Explained by anaphase 1 of meiosis.

33

Dominance

The heterozygote has the same phenotype as the homozygous dominant phenotype.

34

Codominance

The interaction of genes results in heterozygote with its own distinctive phenotype.

35

Lethal allelic combination

One allele in the heterozygous state causes death at an early age.

36

Multiple alleles

More than 2 alleles of a gene are possible.

37

Sex linkage

The gene and its alleles are located on a sex chromosomes most often the X chromosome.

38

Autosomal Recessive

Parents of an affected individual may not be affected.

39

X-linked recessive

More common in males, for a female to be affected the father must be affected. An affected female will pass the trait on to her sons.

40

Autosomal dominant

At least one parent must have been affected

41

X-linked dominant

At least one parent must be affected, an affected father passes it on to his daughters

42

Mendel's Second Law

The segregation of the alleles of a gene is independent of the segregation of the alleles of another gene. Explained by the random assortment of homologous pairs of chromosomes at the equator during metaphase 1 of meiosis, and the subsequent separation in anaphase 1.

43

Polygenic inheritance

More than 2 alleles are involved.

44

Epistasis

One gene influences the expression of another gene.

45

Dihybrid inheritance

The inheritance of alleles at 2 loci.