Unit 2 Molecular Biology

Question 1

Monomers

Answer 1

Small molecule that reacts with similar molecule to form a larger molecule.
Smallest unit in a polymer
Include carbohydrates
Follow basic formula of (CH2O)x
Commonly ring shaped

Question 2

Lipids

Answer 2

Organic molecules
Insoluble in water
Soluble in non-polar solvents
Common lipids include triglycerides (fats and oils), phospholipids and steroids
eg. glycogen

Question 3

Proteins

Answer 3

Contain carbon, hydrogen, oxygen and nitrogen, (sometimes sulphur)
Large, organic compounds made of amino acids
Arranged into one or more linear chains.
Can be structural or part of the plasma membrane
Can also perform other diverse functions in an organism

Question 4

Nucleic Acids

Answer 4

Contain carbon, hydrogen, oxygen, nitrogen and phosphorus
Chains of sub units called nucleotides
Nucleotides consist of base, sugar and phosphate groups covalently bonded together.
If sugar is ribose, RNA is formed
If deoxyribose, DNA is formed.

Question 5

Amino Acids

Answer 5

Contains NH2 (amine group), H, COOH (Carboxyl Group/acidic group) and a central carbon atom
The R group varies depending on amino acid.

Question 6

Fatty Acids

Answer 6

Cahin (or ring) of carbon and hydrogen atoms
H3C-(CH2)n-C=O
                        \OH
No double bond - saturated
1 double bond - Monosaturated
More than 1 double bond - Polysaturated

Question 7

Monosaccharides

Answer 7

Have ring structures in water
Hexose sugar contains 6 carbons
Pentose sugar contains 5 carbons
etc
eg. Glucose, Galactose, fructose, ribose

Question 8

Anabolism

Answer 8

Build molecules
Synthesis of complex molecules from simpler molecules
eg. protein synthesis

Question 9

Catabolism

Answer 9

Break Molecules

eg. digestion

Question 10

Hydrolysis

Answer 10

Breaks Bonds.

eg. Catabolic reactions break down molecules

Question 11

Condensation Reaction

Answer 11

Makes bonds

Eg. anabolism

Question 12

Cohesion

Answer 12

Result of polarity of water molecule

Sticky

Question 13

Adhesion

Answer 13

Result of polarity of water

Water molecules stick to other molecules that are charged.

Question 14

Solvent

Answer 14

Water can disolve many organic and inorganic substances

Question 15

Hydrophilic

Answer 15

Water loving

Can disolve in water

Question 16

Hydrophobic

Answer 16

Water Hating

Can’t dissolve in water

Question 17

Disaccharides

Answer 17

eg. maltose, lactose, sucrose

Question 18

Body Mass Index

Answer 18

Underweight - 18.5>
Normal - 18.5 - 24.9
Overweight - 25 - 29.9
Obese - 30>
Mass in kilos/(hight in metres)^2

Question 19

Ribosomes

Answer 19

Formulate peptide bonds
Site of polypeptide synthesis
mRNA is template

Question 20

Proteome

Answer 20

All proteins produced by a cell, tissue or an organism.
A function of genome and environment which the organism is exposed
Both variable (over time) and unique to every individual (including identical twins and clones).
It reveals what is happening in an organism at a particular time

Question 21

Cytoskeletons

Answer 21

Type of protein

Tubulin is subunit of microtubules that give animals cells their shape and pull on chromosomes during mitosis.

Question 22

Tensile strengthening (collagen)

Answer 22

Type of protein

Fibrous proteins give tensile strength needed in skin, tendons, ligaments and blood vessel walls.

Question 23

Blood clotting

Answer 23

Plasma proteins act as clotting factors that cause blood to turn from a liquid to a gel in wounds.

Question 24

Transport of nutrients and gases

Answer 24

Proteins in blood help transport oxygen, carbon dioxide, iron and lipids.

Question 25

Cell adhesion

Answer 25

Membrane proteins cause adjacent animal cells to stick to each other within tissues.

Question 26

Membrane transport

Answer 26

Membrane proteins are used for facilitated diffusion and active transport Also for electron transport during cell respiration and photosynthesis.

Question 27

Receptors

Answer 27

Binding sites in membranes and cytoplasm for hormones neurotransmitters, tastes, etc

Question 28

Packing of DNA

Answer 28

Histones are associiated with DNA in eukaryotes and help chromosomes to condense during mitosis

Question 29

Rate of Activity

Answer 29

Temperature - Slow increase and fast decrease pH - slow increase and decrease Substrate concentration - slow increase until reaches max, no decrease.

Question 30

Denaturation

Answer 30

If active site changes shape, substrate won't fit | effected by temperature, pH substrate concentration, etc.

Question 31

Lactose Free Milk Production

Answer 31

Lactase bound to surface of alhaniate beads. Milk is passed repeatedly over beads Lactose is broken down in glucose and galactose Immobilised enzyme remains to be used again - doesn't affect quality of lactose free milk.

Question 32

DNA Stucture

Answer 32

``` Double helix Deoxyribonucleic acid (DNA) Adenine and thymine pair Guanine and cytosine pair Phosphate backbone (hydrophilic) connected to nitrogen base antiparallel 3' end is pairs to 5' end of other helix one section is called a nucleoitide. ```

Question 33

RNA Structure

Answer 33

Sinlge stranded Ribonucleic Acid (RNA) Uracil and Thymine pair Cytosine and guanine

Question 34

Nitrogenous Base Pairing

Answer 34

Each of nitrogenous bases can only pair with its partner (A-T and G-C) Called complementary base pairing. Two new strands formed will be identical to original stand. Each new strand contains one original and one new strand, therefore DNA replication is said to be a semi-conservative process. Purines - A, G Pyrimidines - T, C

Question 35

DNA Helicase

Answer 35

Unzips/unwindeds DNA Separates two polynucleotide strands by breaking hydrogen bonds. Two separate strands become parent/template strands for replication

Question 36

DNA Polymerase

Answer 36

``` Creates complementary strands Moves in a 5' to 3' direction 5' end of new strand is starting point Catalase the covalent bonds between sugars and phosphate grounds Proof reads complementary base pairing ```

Question 37

Transcription

Answer 37

Occurs in nucleus RNA polymerase binds to site on DNA at start of a gene It separates the DNA strands and synthesised a complementary RNA copy from antisense DNA strand Done by covalently bonding ribonucleotide triphosphates that align opposite their exposed partner Once completed, RNA polymerase and RNA detatch and double helix reforms. RNA moves to ribosomes to start translation.

Question 38

Translation

Answer 38

Occurs in the ribosome mRNA binds to smaller subunit of ribosome mRNA conatins a series of condons which each of code for an amino acid. tRNA Molecules contain anticodons, complementary to codons tRNA bind to specific amino acids that corresponds to an anticodon Large subunit binds to small subunit of ribosome 3 binding sites of large subunit, only 2 can contain tRNA molecules at a time. ribosome moves along mRNA and presents codons in first two binding sites tRNAs with anticodons and codons bind Peptide bond is formed between two amino acids As ribosome moves, 3rd binding site detaches. Another tRNA carrying an amino acid binds to first site and a 2nd peptide bond is formed the process repeated forming a polypeptide.

Question 39

Messenger RNA

Answer 39

mRNA transcribes a copy of a gene to encode a polypeptide. Length of mRNA molecules varies. Mammal length roughly 2,200 nucleotides (730 amino acids)

Question 40

Codons

Answer 40

64 differend codons which translate to 20 different amino acids Start - AUG Stop - UAA or UAG

Question 41

Transfer RNA

Answer 41

Enables genetic code to synthesise polypeptides

Question 42

Cell Respiration

Answer 42

Controlled release of energy from organic compounds in cells to form ATP.

Question 43

Light

Answer 43

..

Question 44

Temperature Concentration

Answer 44

..

Question 45

Light Concentration

Answer 45

..

Question 46

CO2 Concentration

Answer 46

..

Question 47

Energy

Answer 47

..

Question 48

O2 as Biproduct

Answer 48

..

Question 49

Photosynthesis

Answer 49

A metabolic pathway consisting of light-dependent reactions. | 6CO2 + 6H2O -> C6H12O6 +6O2

Question 50

Cis-Isomers

Answer 50

``` Common in nature H on same side as C2 Double bond causes bend in chain loosely packed triglycerides form from these ```

Question 51

Trans-isomers

Answer 51

``` Rare in nature H on different side to C2 Double bond doesn't cause bend Can be closely packed Triglyceride trans acids are solid at room temp. ```

Question 52

Polymerase Chain Reaction

Answer 52

way of producing large quantities of a specific target sequence of DNA. A repeated Procedure: Denaturation, Annealing and Elongation.