Biological Molecules Flashcards
1
Q
What are Monomers?
A
-Monomers are the smaller units from which larger molecules are made
-Examples include; Monosaccharides, amino acids and nucleotides
2
Q
What are Polymers?
A
-Polymers are molecules made from a large number of monomers joined together
3
Q
What is a condensation reaction?
A
-A condensation reaction joins two molecules together with the formation of a chemical bond and involves the elimination of a molecule of water
4
Q
What is a hydrolysis reaction?
A
-A hydrolysis reactions breaks a chemical bond between two molecules and involves the use of a water molecule
5
Q
What are Monosaccharides?
A
-Monosaccharides are the monomers from which larger carbohydrates are made
-Examples are Glucose, Galactose and Fructose
6
Q
What bond is created in a condensation reaction between two monosaccharides?
A
-A condensation reaction between two monosaccharides forms a Glycosidic Bond
7
Q
What are Disaccharides?
A
-Disaccharides are formed by the condensation of two monosaccharides
8
Q
How is Maltose formed?
A
-Maltose is a disaccharide formed by the condensation of two glucose molecules
9
Q
How Is Sucrose formed?
A
-Sucrose is a disaccharide formed by condensation of a Glucose molecule and a Fructose molecule
10
Q
How is Lactose formed?
A
-Lactose is a disaccharide formed by condensation of a Glucose molecule and a Galactose molecule
11
Q
What are the Isomers of Glucose?
A
-Glucose has two isomers, α-Glucose and β-Glucose
12
Q
How are Polysaccharides formed and describe their solubility in water.
A
-Polysaccharides are formed by the condensation of many Glucose units
-Polysaccharides are insoluble in water
13
Q
How are Glycogen and Starch Formed?
A
-Glycogen and Starch are formed by the Condensation of α-Glucose
14
Q
-How is Cellulose formed?
A
-Cellulose is formed by the condensation of β-Glucose
15
Q
What are Carbohydrates and their uses?
A
-Carbohydrates are Bio-Molecules made of Carbon, Oxygen and Hydrogen
-Cells use Carbohydrates as both a source of energy (typically smaller, simple sugars) or a store of energy(commonly larger complex sugars)
16
Q
What are Pentose Sugars and Hexose sugars?
A
-A Pentose sugar is a Monosaccharide that consists of 5 carbons and have a pentagonal structure
-An example of a Pentose sugar is Ribose
-A Hexose sugar is a Monosaccharide that consists of 6 carbons and have a hexagonal structure
-An example of a Hexose sugar are, Glucose, Fructose and Galactose
17
Q
Describe the structure and uses of starch.
A
-Starch is used for storing energy in plants
-Made of 2 compounds, Amylose and Amylopectin
-Amylose is a polysaccharides that is made from 200-5000 glucose molecules joined by 1,4 Glycosidic bonds
-There is a slight angle between the Alpha-glucoses causing the amylose to be in a spiral shape
-This allows the Amylose to be compact for more space in the cell
-Amylopectin is similar but also has 1,6 Glycosidic bonds which forms branches which are easy to break of the give quick and accessible release of energy
-Starch is also insoluble so doesn’t affect cell water potential
18
Q
What is Amylopectin?
A
-Amylopectin is one of two of the components of Starch
-Amylopectin is branched and is made up of alpha-glucose molecules joined by 1, 4 and 1, 6 glycosidic bonds
- Due to the presence of many side branches these can be acted upon simultaneously by many enzymes and thus broken down to release its energy.
19
Q
What is amylose?
A
-Amylose is an unbranched chain of glucose molecules joined by 1, 4 glycosidic bonds, and as a result amylose is coiled and thus a very compact molecule storing a lot of energy.
20
Q
Describe the structure and uses of Glycogen.
A
-Glycogen is mainly how animals and fungi store energy
-Glycogen is formed from many molecules of alpha glucose joined together by 1, 4 and 1, 6 glycosidic bonds. -It has a large number of side branches meaning that energy can be released quickly as enzymes can act simultaneously on these branches.
21
Q
Describe the structure and uses of Cellulose.
A
-Cellulose is a strong substance found in plant cell walls, which stops the cell from bursting
-It is made up of unbranched chains of Beta-glucose molecules linked via 1,4 glycosidic bonds
-Every alternate glucose molecule in cellulose chains is inverted to avoid a spiral structure
-These chains are arranged by lining up on top of each other like a brick wall bonded by hydrogen bonds; These structures are called Microfibrils
-Most animals, including humans, cannot digest cellulose as they lack enzymes, however cows can
22
Q
Describe the structure of Microfibrils.
A
-Microfibrils are strong threads which are made of long cellulose chains running parallel to one another that are joined together by Hydrogen bonds forming strong cross linkages
23
Q
Describe a Biochemical test for reducing sugars.
A
-Benedict’s reagent can be used to test for the presence of reducing sugars, which are sugars that can reduce the Benedict’s reagent (an alkaline solution of Copper (II) Sulfate)
-When a reducing sugar is added to this blue reagent and heated, it forms an insoluble brick red precipitate (Copper (I) oxide)
24
Q
Describe the Biochemical test for non-reducing sugars.
A
-If a sugar is added to Benedict’s reagent and there is no colour change from blue to brick red, the food sample is a non-reducing sugar
-Therefore, dilute HCl is added and heated to hydrolyse the glycosidic bonds between the polysaccharides and disaccharides
-Then Sodium Hydrogen-carbonate is added in order to neutralise the solution as Benedict’s reagent wont work in acidic solutions
-Then the reducing sugar test is repeated- if sugars are present Benedict’s reagent changes from blue to brick red
25
Describe the Biochemical test for starch.
-A chemical test for starch is **iodine/potassium iodide**
-If the solution turns **blue/black in colour from orange-brown** then starch is present
26
What are Reducing and Non-reducing sugars?
-Reducing sugars are Monosaccharides and some Disaccharides (e.g maltose) that are reducing agents
-Non-reducing sugars are Polysaccharides that are not reducing agents
27
Describe the structure of Triglycerides and how they are formed.
-Triglycerides are formed by the condensation of **one molecule of glycerol and three molecules of fatty acid** to form **three ester bonds**
-They are **non-polar molecules** and therefore **insoluble in water** (waterproof)
-The great amount of Carbon and Hydrogen means that when these bonds are broken, a great amount of energy can be released
28
Describe the function and properties of Triglycerides.
-**High ratio of energy strong carbon-Hydrogen bonds to carbon atoms** and therefore they are an excellent energy store
-**A low mass to energy ratio** meaning that they are a good storage molecule, with **a lot of energy being stored in a small volume.** This is beneficial for animals as it is **less mass to move around**
-**Insoluble in water and therefore does not affect cell water potential**
-**A high ratio of hydrogen-oxygen atoms** means that **triglycerides release water when they are oxidised** providing water for organisms living in a dry environment
29
What are lipids and what are they used for?
-Lipids are Biological molecules made of Carbon, Hydrogen and oxygen
-**Lipids are only soluble in organic solvents and alcohols**
-The main types are **triglycerides and phospholipids**
-They are used to **regulate hormones, transmit nerve impulses and store energy in the form of body fat**
30
What are saturated lipids?
-Saturated lipids are found in **animal fats**
-Saturated lipids **don’t contain any carbon-carbon double bonds**
31
What are unsaturated lipids?
-Unsaturated lipids can be found in **plants**
-Unsaturated lipids **contain carbon-carbon double bonds**
-The presence of of a double bond means that the molecule is **able to bend**
-As a result, unsaturated fats **cannot pack together as tightly and are therefore liquid at room temperature**
-Also known as **trans-fats** which are very unhealthy for humans as it **raises bad cholesterol and lowers good cholesterol** blocking arteries. This is for **the bending means we as humans don’t have the enzymes to break the trans-fats down**
-They can be **monounsaturated,** containing one double bond, or **polyunsaturated** containing multiple double bonds
32
Describe the bonding between a Glycerol and a fatty acid (RCOOH).
-A condensation reaction between glycerol and a fatty acid forms an ester bond
33
Describe the structure and function of Phospholipids.
-In phospholipids, one of the fatty acids of a triglyceride is substituted by a **phosphate containing group**
-The fatty acids tails are **hydrophobic** and the phosphate head is **hydrophilic,** meaning that phospholipids are **polar molecules**
-The polarity means that in **aqueous environments** a **phospholipid bilayer** can be formed
-Their structure allows them to form **glycolipids with carbohydrates** which are important on the cell surface for **cell recognition**
34
What is the Biochemical test for lipids?
-An **emulsion test** can be used for the presence of lipids
-Mix **ethanol** and the liquid food sample together and **shake thoroughly to dissolve the lipid in the solution**
-Then **add water and shake gently**, a **cloudy white emulsion should settle at the top of the solution if lipids are present**
-For a control group the experiment can be repeated with water taking the place as the food sample to show no white emulsion forming
35
What are fatty acids?
-Fatty acids are different length **Hydrocarbon chains** with a **carboxyl group** at the end, hence the ‘acid’
-They are **hydrophobic and non-polar** because the symmetrical hydrocarbons have no dipole
-The general formula for a saturated acid is **CnH*2n02**
-**2 Hydrogen’s are removed per C-C double bond** in unsaturated fats
36
Describe the bonding between amino acids
-A condensation reaction between two amino acids forms a **peptide bonds**
37
How are dipeptides formed?
-Dipeptides are formed by the condensation of two amino acids
38
How are polypeptides formed?
-Polypeptides are formed by the condensation of many amino acids
39
What are amino acids?
-Amino acids are the monomers from which proteins are made
-They all contain an **Amino group** and a **carboxyl acid group** with a variable **R group**
-Amino acids contain **C,H,O,N and sometimes S**
-There are only 20 types of amino acids
40
Describe the structure of Amino acids.
-Amino acids have the structure of an **amino group (NH2)**, a **carboxylic acid group (COOH)** and a **variable R group** attached to a **CH**
41
what are the levels of structure of proteins?
-Structure of proteins is determined by the order and number of amino acids, bonding present and the shape of protein and is categorised as the structures below:
-Primary structure; **the order and number of amino acids in a protein**
-Secondary structure; the shape that the chain of amino acids - either **alpha helix and beta pleated sheets**
-Tertiary structure; the **3d shape of the protein** and is formed from further twisting and folding and is **maintained by bonding** in the proteins such as **Disulfide bridges, Ionic bonds and Hydrogen bonds**
-Quaternary structure; when one or more 3d polypeptides chain together
42
What are Globular and Fibrous proteins?
-**Globular proteins** are proteins such as enzymes and they are **compact proteins**
-**Fibrous proteins** and proteins such as keratin which are **long and thus can be used to form fibre**
43
What is the Primary structure of a protein?
-Primary structure of a protein is the **order and number of amino acids in a protein.** This primary structure **contains the initial sequence of amino acids** and therefore **determine the proteins function** at the end of the
44
What is the secondary structure of a protein?
-The Secondary structure is the shape that the chain of amino acids which is either an **alpha helix **or a **beta pleated sheet held by hydrogen bonds**
45
What is the tertiary structure of a protein?
-Tertiary structure of proteins is the **3D shape of the protein and is formed form further twisting and folding.** A number of different **bonds maintain structure, these are Disulfide bridges, Ionic bonds and Hydrogen bonds.**
46
What are Disulfide bridges?
-Disulfide bridges are interactions **between the sulfur in the R Group of the amino acid Cysteine**
47
What are ionic bonds (proteins)?
-Ionic bonds **form between the Carboxyl and amino groups** that are not involved in the peptide bonds.
-They are **easily broken by pH** and are weaker than disulfe bdrifges
48
Describe the biochemical test for proteins
-The biochemical test for proteins is using the **Biuret test** as it tests for the presence of peptide bonds
-You first add an **equal amount of sodium hydroxide** then a few drops of **very dilute Copper (II) sulfate** and **mix gently**
-A positive test indication the presence of a peptide bond and hence proteins turns the solution **from blue to purple**
49
Describe the method for paper chromatography
-A **spot of the mixture that you want separated** is placed on chromatography paper on a starting line drawn in pencil so it does not dissolve then **left to dry**
-The paper is then suspended in a **solvent**
-As the Solvent travels through the paper, the **different components of the mixture being to move up** the paper at different speeds
-**Larger molecules move slower than the smaller ones causing the mixture to separate out** into different spots or bands on the paper producing a **chromatogram**
50
What is Chromatography?
-Chromatography is a technique that can be used to separate mixtures into its individual components
-It **relies on different solubilities** of the chemicals being tested which can then be compared to **known standard solutions** to compare and figure out what the unknown solution is made from
-**More soluble chemicals travel further**
-The start line in chromatography is drawn in **pencil as graphite is insoluble whereas the dyes that make up the ink are**
51
What are enzymes?
-Enzymes are **globular proteins**
-They have high specificity and **often only catalyse one reaction**
-Enzymes are **biological catalysts** that speed up the reaction by **decreasing the activation energy** of the reaction it catalyses
52
Why are do enzymes have high specificity?
-The **tertiary structure of an enzymes active site is extremely specific**
-Only **complementary substrates** can bind to form an **enzyme-substrate complex**
53
What are enzyme inhibitors?
-Enzyme inhibitors are **substances that prevent enzymes from working**
-This can be done **reversibly or irreversibly**
-There are **competitive inhibitors** that share the shape of the substrate that alternatively fits into the active site
-And there are **non-competitive inhibitors** that bond to a different site on the enzyme, changing the shape of the active site
54
What are competitive inhibitors?
- A phenomenon in which a **substrate molecule** is **prevented from binding to the active site** of an enzyme **by a molecule that is very similar in structure to the substrate**.
-Thus, the inhibitor molecule and the substrate that the enzyme acts on “compete” for the same binding site.
55
What are non-competitive inhibitors?
-Non-competitive inhibitors **bind to a different site** on the enzyme, **changing the shape** of the enzyme so that it **cannot bind to the substrate effectively**
56
What are the two theories of how enzymes work?
-**Lock and key;** the active site exactly fits the substrates its trying to catalyse and once a complex forms between the two to form the products of the reaction
-**Induced fit;** the active site is not a perfect match for the substrate, rather clamps down around the substrate forming an induced fit
57
What types of enzymes are there?
-Enzymes can break things down in a **catabolic reaction** or build something up in an **anabolic reaction**
-Enzymes can work inside cells as **intracellular enzymes** or outside as **extracellular enzymes**
58
What is the lock and key theory (enzymes)?
-The Lock and Key Theory uses a lock and key metaphor to explain how enzymes and substrates interact.
- The 'lock' represents the enzyme and the 'key' the substrate.
-The substrate fits perfectly into the enzyme's active site, catalysing a reaction in a way similar to a key opening a lock.
59
What is the induced fit model (enzymes)?
-After analysis and research on the lock and key theory, it seems to simple to be plausible, rather the idea of an active site not perfectly fitting the substrate is more reasonable
-When the enzyme and substrate bind and form an **enzyme-substrate complex**, the **structure of the enzyme is altered** so that **the active site of the enzyme fits around the substrate**
-This happens by clamping down forming an induced fit
-It has been theorised this is why enzymes are so specific as it has a **two stage verification process**, first the substrate has to bind to the active site then **correctly alter its shape**
60
What are the factors affecting the rate of enzyme-controlled reactions?
-**enzyme concentration;** higher concentration increases the rate of successful collisions for their is a higher chance of a collision between enzyme and substrate
-**Substrate concentration;** The rate increases as their is a higher chance of successful collisions until all the active sites of the enzymes are full and the rate plateaus, this is known as as the V-max
-**Temperature;** more kinetic energy means that there is more collisions as substrates and enzymes move around faster so higher rate. However this has to work within the realm of enzymes optimum Temperature because if its too hot, enzymes will denature
-**pH;** increases the rate within the optimum pH, if not it just denatures the enzyme and its active site
61
What is the active site and substrates (enzymes)?
-The active site of an enzyme is an **area that is made up of only a few amino acids** and forms a small depression in the overall enzyme
-The molecule that the enzyme acts upon is called the substrate
62
How does Tempereture affect the rate of enzyme-controlled reactions?
-Rate of reaction **increases up until the optimum Temperature** as the **kinetic energy of the enzyme increases** (more successful collisions)
-**Above the optimum temperature the rate decreases** as enzymes become **denatured**
63
How does pH affect the rate of enzyme-controlled reactions?
-The ph affects the enzymes shape as it can disrupt the bonds in the tertiary structure of the enzyme; **pH denatures the enzyme**
-**Therefore the rate increases around the optimum pH**
64
How does enzyme concentration affect the rate of enzyme-controlled reactions?
-the rate of reaction **increases** as enzyme concentration increases as there are **more active sites for substrates to bind to**
-However, beyond a certain point, **substrate concentration becomes a limiting factor** as there are more active sites than substrates, so the **rate plateaus**
65
How does substrate concentration affect the rate of enzyme-controlled reactions?
-As substrate concentration increases, the rate of reaction increases as more enzyme-substrate complexes are formed
-However at a certain point, **the enzyme concentration becomes a limiting factor** as there are no more active sites for the substrate to bond to hence the **rate plateaus**
66
How are enzymes denatured?
-**Bonds are broken changing the tertiary structure**
-Hence they do not work
-**pH and Temperature** can break bonds and **denature** an enzyme
67
Describe water molecules.
-They are (Di) **Polar molecules** for charge is unevenly distributed across the molecule as **oxygen has a negative charge and hydrogen a positive charge**
-**Hydrogen bonds form between oxygen and hydrogen**
(The hydrogen is attracted to the electronegative region of lone pairs on oxygen)
68
What are the Properties of water?
-Water is a **metabolite**, as it is involved in many important reactions
-Water is a **polar solvent** as lots of polar molecules can dissolve in it
-Water has a **high specific heat capacity** meaning that water requires lots of energy to raise its temperature
-Water has a **large latent heat of vaporisation** meaning lots of energy is required to convert is to a gas from liquid
-Water has **strong cohesion** due to hydrogen bonding
69
Why is Water a metabolite?
-Water is involved in may reactions such as photosynthesis, hydrolysis and condensation
-Water is known as a metabolite as it is **a molecule that takes place in metabolic reactions**, which are, biochemical reactions that takes place in a living organism in order to keep them alive
-It is **often a needed reactant** e.g hydrolysis reactions
70
What are metabolic reactions?
-biochemical reactions that takes place in a living organism in order to keep them alive
71
Why is water a good solvent?
-**Waters polarity allows it to be a good polar solvent** as it **can attract both negative and positive ions** of polar molecules
-Furthermore, it a hydrogen bonded to a strongly electronegative element and a lone pair allowing for hydrogen bonding
-**It is an important solvent in which metabolic reactions can occur**
72
What is high specific heat capacity of water?
-This means that water **requires lots of energy to raise its Tempereture**
73
Why does water have a high specific heat capacity?
-This is because **most of the heat energy is required to overcome or break the hydrogen bonds**
-This is useful to organisms as the **temperature of water will remain fairly stable regardless of external temperatures**. Therfore, internal Temperatures of plants and animals should remain roughly the same regardless of external temperetures due to the fact that they are largely comprised of water
-**This ensures that enzymes do not denature or reduce in activity with temperature fluctuations**
74
What does water has a large latent heat of vaporisation mean?
-It means that a lot of energy is requires to convert water to a gaseous state from a liquid state
75
Why does water have a large latent heat of vaporisation?
-**A lot of energy is required to convert water in its liquid state to a gaseous state** due to **strong hydrogen bonds that require lots of energy to overcome**
-This is useful as it **provides a cooling effect**- when humans sweat, **lots of heat energy is transferred to the water to evaporate it**, therefore removing a lot of heat energy from the organism
76
Why does water have strong cohesion?
-**Cohesion is waters ability to stick together due to hydrogen bonding**
-Due to molecules sticking together, **water moves up the xylem of plants due to transpiration in a constant continuous column of water**. This is **advantageous as it is easier to draw up a column rather than individual molecules**
-Cohesion also provides surface tension to water as it enables small invertebrates to move and live on the surface providing them a habitat away from predators within water
77
How is water a buffer?
-Waters high specific heat capacity means that it can be used as buffer for changes in temperatures
78
How does water provide a cooling affect?
-Due to water having a relatively large latent heat of vaporisation, it has a cooling affect as lots of heat energy is transferred to the water when evaporating it, removing heat energy from the organism
79
What are Hydroxide ions (inorganic ions)?
-Hydroxide ions are **bases**
-A **high concentration of hydroxide ions in a solutions will make the solution alkaline**
80
What are inorganic ions?
-**Inorganic ions occur in solution in the cytoplasm and body fluids** of organisms, some in high concentrations and others in very low concentrations.
81
What are Hydrogen ions (inorganic ions)?
-**Hydrogen ions are acids**
-The concentration determines the pH do a substance such as blood, **the higher the concentration of hydrogen ions, the lower the pH**
82
What are some essential inorganic ions?
-**Hydrogen ions which determine the pH** of substances such as blood
-**Iron ions are a component of haemoglobin** which is an oxygen carrying molecule in red blood cells
-**Sodium ions are involved in co-transport of glucose and amino acids**
-**Phosphate ions are a component of DNA and ATP**
83
What is the difference between organic and inorganic ions?
-**An organic ion contains carbon**
-**An inorganic ion doesn’t contain carbon**
84
What is the function of DNA?
-**Deoxyribonucleic acid** codes for the **sequence of amino acids** in the primary structure of a protein which in turn **determines the tertiary structure** and **hence function** of the protein
-Therefore it is **essential** that cells contain a **copy of this genetic code** and that it can be **passed onto new cells without being damaged**
85
What are nucleotides?
-Nucleotides are the monomers that makes up **nucleic acids** such as DNA, RNA and ATP
-It consists of a Pentose sugar, a nitrogenous base and a phosphate group
86
Describe the structure of DNA.
-DNA is a **long polynucleotide** and has a **double helix structure**
-It consists of the nucleotide made from a negatively charged **phosphate group**, a **nitrogenous base** and a pentose sugar, **Deoxyribose**
-Two polynucleotide strands are bonded via **hydrogen bonds**
-The nitrogenous bases in DNA are, **Adenine, Guanine, Cystine and Thymine**
-Between the complimentary bases Cystine and Guanine, **three hydrogen bonds** are made
-Between the complimentary bases Adenine and Thymine, **two hydrogen bonds** are made
-It is long to carry **lots of information**
87
How is a dinucleotide formed?
-It is created via a **condensation reaction** between the **pentose sugar** and the **phosphate group** forming a **phosphodiester bond** (and water is produced)
-These are **strong covalent bonds** ensuring that the **genetic code is not broken down**
-This is often described as the **sugar-phosphate backbone **due to the strong covalent bonds and the phosphate groups that hold the polymer together
88
How is a polynucleotide formed?
-It is created via a **condensation reaction** between the **pentose sugar** and the **phosphate group** forming a **phosphodiester bond** (and water is produced)
-These are **strong covalent bonds** ensuring that the **genetic code is not broken down**
-This is often described as the **sugar-phosphate backbone **due to the strong covalent bonds and the phosphate groups that hold the polymer together
89
What are the complimentary base pairs in DNA?
-**Complimentary base pairings allow identical copies to be made**
-In DNA, **Adenine pairs with Thymine** and **Guanine pairs with Cystine**
- **Three Hydrogen bonds** is made between **Cystine and Guanine**
-**Two hydrogen bonds** is made between **Adenine and Thymine**
90
How many Hydrogen bonds are made between complimentary base pairings (DNA)?
-**Two Hydrogen bonds** are made between **Adenine and Thymine**
-**Three Hydrogen** bonds are made between **Guanine and Cystine**
91
What is the function of RNA?
-The function of RNA is to **copy and transfer the genetic code from DNA in the nucleus to the ribosomes**
-**Some RNA** (rRNA) **is also combined with proteins to create ribosomes**
92
Describe the structure of RNA.
-It is a **single stranded** and relatively **short polynucleotide chain**
-It can have the nitrogenous bases, Adenine, Cystine, Guanine and **Uracil**
-It is made of nucleotides consisting of the pentose sugar **ribose**
93
What are the differences between DNA and RNA?
-RNA is **single stranded** whereas DNA is a **double helix**
-The pentose sugar in the nucleotide making DNA is **Deoxyribose** whereas the pentose sugar in RNA is **ribose**
-In RNA, the nitrogenous base **Uracil is a replacement of Thymine**, a nitrogenous base in DNA
94
How does the structure of DNA relate to its function?
-**Stable structure** due to sugar-phosphate backbone and double helix structure
-Double stranded so **replication can occur using one strand as a template**
-**Weak hydrogen bonds** between nitrogenous bases and strands for **easy unzipping during replication**
-Large, long molecule to **carry lots of information**
-Complimentary base pairings allow **identical copies to be made**
95
Why is DNA replicated?
-Before cells divide, all the DNA **must be replicated** to provide a **copy for the new cell**
-**The semi-conservative replication of DNA ensures genetic continuity between generations of cells**
96
What does semi-conservative replication mean?
-Semi-conservative replication means that in the two daughter cells as the product of replication, **one strand is from the parental DNA** and one strand is **newly synthesised**
-** semi-conservative replication of DNA ensures genetic continuity between generations of cells**
97
What does semi-conservative replication ensure?
-** semi-conservative replication of DNA ensures genetic continuity between generations of cells**
98
What does DNA Helicase do?
-The **enzyme** DNA Helicase **breaks the hydrogen bonds between complimentary bases** in DNA
-This causes the DNA **double helix to unwind**
99
What does DNA Polymerase do?
-The **enzyme** DNA polymerase **catalyses the condensation reaction between adjacent nucleotides**
-This happens during semi-conservative replication
-DNA polymerase **joins the adjacent nucleotides via a condensation reaction to form phosphodiester bonds**
100
Describe the process of Semi-conservative replication.
-**DNA Helicase breaks hydrogen bonds** between complimentary pairs in the Parent DNA
-This causes the **double helix to unwind**
-The **separated parental strands act as a template**
-**Free floating nucleotides** within the nucleus are attracted to their complementary base pairs on the template
-**Condensation reaction occur between adjacent nucleotides** this forming **phosphodiester bonds**
-This is **catalysed by DNA Polymerase**
101
What is the first step of semi-conservative replication?
-The enzyme **DNA helicase breaks the hydrogen bonds between the complementary base pairs** between the two strands within a double helix
-This causes the DNA **double helix to unwind**
102
What is the second step of semi-conservative replication?
-Each of the **Separated parental DNA strands act as a template**
-**Free floating DNA nucleotides within the nucleus are attracted to their complementary base pairs** on the template strands of the parental DNA
103
What is the third step in semi-conservative replication?
-**The adjacent nucleotides are joined together to form the phosphodiester bonds by a condensation reaction**
-**DNA polymerase catalyses the joining together of adjacent nucleotides**
104
What is ATP?
-**Adenosine triphosphate** is a **nucleotide derivative** and consists of **Adenine, ribose and three phosphate groups**
105
What is the function of ATP?
-It is an **immediate source of energy** for biological processes. **Metabolic reactions** in cells **must have a constant, steady supply of ATP**
106
How can ATP be made?
-ATP is made **during photosynthesis and respiration**
-This happens via a **condensation reaction** between **adenosine diphosphate (ADP)** and **Inorganic phosphate (PI)**
-This reaction uses the enzyme **ATP synthase**
107
What is ATP synthase used for?
-ATP synthase is an enzyme used in photosynthesis and respiration to **catalyse the condensation reaction of PI and ADP to produce ATP**
108
Describe the Hydrolysis of ATP.
-ATP can be hydrolysed into **Adenosine diphosphate (ADP)** and **inorganic phosphate (PI)**
-This is catalysed by **ATP Hydrolase**
-This releases a small amount of energy
109
Why is the hydrolysis of ATP important?
-ATP can transfer energy to other compounds
-The inorganic phosphate released during the hydrolysis of ATP can be **bonded onto different compounds to make often them more reactive.** This is known as as **phosphorylation**
-This happens to glucose at the start of respiration to make it more reactive
110
What is phosphorylation?
-Phosphorylation is when an **inorganic phosphate**, released during the hydrolysis of ATP, is **bonded to different compounds to make them more reactive**
-This happens to glucose at the start of respiration
111
What does ATP hydrolase do?
-ATP can be **hydrolysed** into ADP and PI (inorganic phosphate) **using enzyme ATP hydrolase**. This releases a small amount of energy
