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3.1 Biological molecules Flashcards

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1
Q

What are monomers?
Give three examples

A

small molecular units from which larger molecules are made
(Monosaccharides, amino acids and nucleotides

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2
Q

What are polymers?
Give three examples

A

Molecules made from a large number of molecules joined together
(Carbohydrates, proteins, nucleic acids)

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3
Q

What is a condensation reaction?

A

joining two molecules together with the formation of a chemical bond and a water molecule
(Forming a disaccharide or polysaccharide)

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4
Q

What is a hydrolysis reaction?

A

breaks a chemical bond between two molecules and involves the use of a water molecule

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5
Q

What is the bond formed during a condensation reaction?

A

a GLYCOSIDIC bond

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6
Q

What are monosaccharides?
Give three examples

A

monomers from which larger carbohydrates are made
(Glucose, galactose, fructose)

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7
Q

What are disaccharides?

A

formed via the condensation of two monosaccharides

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8
Q

What are the three main disaccharides and what are they made from?

A

Maltose (2 glucose molecules)
Sucrose (1 glucose and 1 fructose)
Lactose (1 glucose and 1 galactose)

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9
Q

What is an isomer?

A

SAME molecular formula but the atoms are connected in a different way

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10
Q

What are the two isomers of glucose?

A

Alpha glucose (OH at bottom)
Beta glucose (OH at top)

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11
Q

What are polysaccharides and give three examples?

A

condensation of many (2+) glucose units
-Glycogen and starch are made of a-glucose
-cellulose is made of** b-glucose**

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12
Q

Give the structure and function of starch

A

Structure: amylose and amylopectin
Function: Main energy storage material in plants
* Insoluble so has no impact on water potential
* Compact so lots can be stored
* Release alpha glucose easily when hydrolysed due to the many branched ends in amylopectin - readily used in respiration

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13
Q

Give the structure and function of glycogen

A

Structure: alpha glucose joined by 1,4 and 1,6 glycosidic bonds
Function: Main energy storage material in animals
* insoluble so does not impact water potential
* Large so does not diffuse out of cells
* compact so lots can be stored
* more highly branches than starch - more rapidly broken down to form glucose which is important as animals have a higher metabolic rate and therefore respiratory rate than plants

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14
Q

Give the structure and function of cellulose

A

Structure: long chains of β-glucose joined together by 1,4 glycosidic bonds, many parallel hydrogen cross links for strength (straight and unbranched)
Function: structure in plant cell walls
* high tensile strength means plants can withstand osmotic pressure

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15
Q

How does cellulose get its strength?

A

Microfibrils- Strong fibres made of long cellulose chains joined parallel by hydrogen bonds

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16
Q

Give the structure of amylose

A

Unbranched helix-shaped chain with 1,4 glycosidic bonds between α-glucose molecules
* Coiled and compact so good for storage

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17
Q

Give the structure of amylopectin

A

1,4 glycosidic bonds between α-glucose molecules but also 1,6 glycosidic bonds form between glucose molecules creating a branched molecule
* enzymes can easily reach glycosidic bonds for faster glucose release in respiration

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18
Q

Describe the chemical test for reducing sugars

A

Benedicts test
* add benedicts to sample
* **heat **in water bath (that has been brought to the boil)
* Positive (Coloured precipitate, varying from green to brick red based on concentration)

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19
Q

Describe the chemical test for non-reducing sugars

A
  • Add dilute Hcl to sample, place in water bath (addition of acid will hydrolyse any glycosidic bonds present in any carbohydrate molecules)
  • add sodium hydrogencarbonate (neutralises solution)
  • retest with benedicts in water bath
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20
Q

Describe the chemical test for starch

A

Iodine test
* add iodine dissolved in potassium iodide solution
* Starch present = Orange to blue-black

Potassium iodide is added as iodine is insoluble in water

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21
Q

What are triglycerides?

A

Energy storage molecule
formed by condensation of one molecule of glycerol and three fatty acids

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22
Q

What type of bond is formed during condensation of triglycerides and phospholipids?

A

ester bond

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23
Q

What type of bond is formed during condensation of amino acids?

A

peptide bond
(to form a polypeptide-protein)

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24
Q

What are the properties of a saturated fatty acid R-group?

A

No double bonds between carbons
(Animal fats)

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25
Q

What are the properties of an unsaturated fatty acid R-group?

A

1+ double bonds
(Molecule bends so liquid at room temp)

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26
Q

What are the 3 elements which make up lipids ?

A

carbon, hydrogen and oxygen

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27
Q

Describe the structure and properties of triglycerides

A
  • ** Long hydrocarbon tails** = when triglycerides are oxidised during respiration this causes these bonds to break releasing more energy per gram than carbs or protein
  • form insoluble droplets which are hydrophobic = no impact on water potential so can be stored
  • low mass to energy ratio = lots of energy in a small volume
  • high ratio of hydrogen to oxygen atoms so water is released when oxidised
  • Also provides buyoncy and insulation

Fatty acid tails are hydrophobic while glycerol molecules are hydrophillic

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28
Q

What are phospholipids?

A

Bilayer of cell membranes
one of the fatty acids is replaced by a phosphate containing group

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29
Q

Describe the structure and properties of phospholipids

A
  • Bilayer (Polar phosphate points outwards, non-polar fatty acid points inwards creating a hydrophobic core) = barrier to water soluble molecules

Fatty acid tails are hydrophobic while phoshate group is hydrophillic

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30
Q

Are triglycerides polar or non-polar?

A

Non-polar (hydrophobic so do not impact water potential)

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31
Q

Are phospholipids polar or non-polar?

A

Polar phosphate head (but non-polar fatty acid tails)

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32
Q

Describe the chemical test for lipids

A

* Shake test solution with ethanol
* Add to water and shake
* Cloudy white emulsion shows a positive test

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33
Q

Give the main four uses of lipids

A
  • cell membranes
  • energy - twice as much as carbohydrates or protein
  • waterproofing - insoluble in water
  • insulation - fats are slow conductors of heat and act as electrical insulators around the mylein sheath
  • protection around delicate organs
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34
Q

What are amino acids?

See diagram via link

A

monomers from which proteins are made

http://www.a-levelnotes.co.uk/uploads/9/6/0/2/96027112/published/52-amino-acid-structure.png?1566484809

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35
Q

How many types of amino acids are there?

A

20 (only the side chain (R) changes

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36
Q

What type of bond is formed between a condensation reaction of two amino acids?

A

Peptide bond

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37
Q

How is a peptide bond formed?

A

hydroxyl (-OH) is lost from the carboxylic group of one amino acid and a hydrogen atom is lost from the amine group of another amino acid
-The remaining **carbon and nitrogen **atoms then bond

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38
Q

What are dipeptides?

A

Formed by the condensation of two amino acids

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39
Q

What are polypeptides?

A

Formed by the condensation of many amino acids

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40
Q

What is a functional protein?

A

may contain one or more polypeptides
(These include haemoglobin, insulin, enzymes)

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41
Q

Describe the primary structure of proteins

A

specific sequence of amino acids in a polypeptide chain (DNA arranges order of amino acids in the primary structure)

Amino acids are joined by COVALENT PEPTIDE bonds

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42
Q

Describe the secondary structure of proteins

A

Hydrogen bonds form between the amino acids, causing them to coil/fold

weak negatively charged nitrogen and oxygen atoms interact with the weak positively charged hydrogen atoms

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43
Q

What is the alpha helix?

A

amino acids COIL, forming hydrogen bonds between every fourth peptide bond

Type of secondary structure

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44
Q

What is the beta pleated sheet?

A

amino acids FOLD, 2 parts of chain are parallel so hydrogen bonds form between peptide bonds

Type of secondary structure

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45
Q

Describe the tertiary structure of proteins

A

Further coiling/folding so more bonds form (between the R groups)

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46
Q

Describe the role of hydrogen bonds in tertiary proteins

Where do they form ?

A

form between strongly polar (Hydrophillic) R groups
-Weakest but most common bond

R groups

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47
Q

Describe the role of ionic bonds in tertiary protein structure

A

form between positively charged amine and negatively charged** carboxylic acid** R groups
-Stronger than hydrogen bonds but uncommon

CHARGED R groups

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48
Q

Describe the role of disulfide bridges in tertiary protein structure

A

form strong covalent bonds between cysteine amino acid R groups
-The sulfurs bond
-These are strong but infrequent and help to stabalise the protein

49
Q

Describe the chemical test for proteins

A

Biurets
* Treat sample with sodium or potassium hydroxide to make it alkaline
* add biurets
* Colour should change from blue to lilac if protein is present

(Must be at least TWO peptide bonds, amino acids of dipeptides will give a positive result)

50
Q

Give five functions of proteins

A
  • Enzymes
  • Antibodies
  • Transport proteins
  • Structural proteins
  • Hormones
51
Q

Describe the structure and function of enzymes

A

Structure: tight folding and spherical shape
-Soluble so have roles in metabolism and protein synthesis

52
Q

Describe the structure and function of Antibodies

A

Structure: Two short and two long polypeptide chains bonded together
-Used in immune response

53
Q

Describe the structure and function of transport proteins

A

Structure: Hydrophobic and hydrophillic amino acids so protein folds and forms a channel
-Means it can transport ions and molecules across membranes

54
Q

Describe the structure and function of structural proteins

A

Structure: Parallel polypeptide chains with cross links
-Used in karatin and collagen

55
Q

How does the structure of globular proteins link to their function ?

Give some examples of globular proteins

A

They are compact, spherical (stabilised by bonds) and soluble (Hydrophobic R groups face in while hydrophillic R groups face out)
Function (Functional) = solubility means they can easily be transported across cell membranes for metabolic reactions

Eg. enzymes, haemoglobin, immunoglobins, insulin

56
Q

How does the structure of fibrous proteins link to their function ?

Give some examples

A

Long chain of amino acids in a repetitive sequence which are coiled/folded, several polypeptide chains are joined by hydrogen bonds to form fibres/sheets
Function (structural):
Fibres = provide strengh (eg keratin)
Sheets = provide flexability (eg collagen)
-generally insoluble (external R-groups are non-polar, aka hydrophobic)

Keratin (hair and nails) , Collagen (connective tissue)

57
Q

Define enzyme

A

tertiary structure enzymes which act as biological catalysts to increase rate of chemical reactions

58
Q

Describe how the structure of enzymes relates to their function

A
  1. They have a** specific active site** (due to folding in the tertiary structure)
  2. Which will bind to the complementary substrate
  3. To form an enzyme substrate complex
59
Q

How do enzymes speed up chemical reactions ?

A

they lower the activation energy
* Method 1 = enzyme holds substrate molecules close, reducing repulsion so they bind more easily
* Method 2 = enzyme in the active site puts strain on the bonds so they break down faster

60
Q

What is the lock and key model of enzyme action ?

A

Enzyme active site has a fixed shape which is complementary to the substrate

61
Q

What is the induced fit model of enzyme action ?

A
  • substrate is almost complementary
  • active site is induced to mould around the substate
  • enzyme-substate complex puts strain on bonds in the substrate
  • lowering the activation energy
62
Q

*Describe the effect of temperature **on enzyme action, up to the optimum point

A
  • As temperature increases
  • The **kinetic energy **of the enzyme and substrate molecules increases
  • so there are more collisions
  • which means more enzyme substrate complexes form between enzyme and substrate
  • highest rate of reaction is the** optimum point**
63
Q

Describe the **effect of temperature **on enzyme action, if it gets too high

A
  • At the optimum point kinetic energy is greatest so molecules collide with the enzyme more often
  • The **vibrations **can cause the hydrogen, ionic and disulphide bonds in the tertiary structure to break
  • This changes the shape of the active site
  • So it is no longer complementary to the substrate
  • so enzyme substrate complex cannot form, enzyme has been denatured
64
Q

Describe the effect of pH on enzyme action

A

changing pH can impact the enzyme action in two ways:
* extreme pH breaks the hydrogen,ionic and disulphide bonds in the tertiary structure causing the active site to change shape
* can **affect the charges **on the amino acid in the active site, so the substrate can no longer attach

65
Q

Describe the effect of **enzyme concentration **on enzyme action

A
  • as enzyme concentration increases
  • there will be more **successful collisions **between the active sites and the substrates
  • so more enzyme substrate complexes form, increasing rate of reaction
  • eventually** rate will plateau, **as all the substrates have been used up (Maximum enzyme substrate complexes)
66
Q

Describe the effect of substrate concentration on enzyme action

A
  • as substrate concentration increases
  • there will be more successful collisions between the active site and the substrate
  • so more **enzyme substrate complexes **form, increasing rate of reaction
  • At the saturation point all the active sites are full, so rate plateau’s and increasing substrate further has no impact (Maximum enzyme substrate complexes)
67
Q

Explain why changing one amino acid in the primary structure of a protein could prevent it from functioning ?

Exam question

A
  • Primary structure is the sequence of amino acids in a polypeptide chain
  • If amino acid changes hydrogen bonds form ina different place so it folds differently in the secondary structure
  • Ionic and disulfide bonds will then form in different places which changes the shape of the tertiary structure
  • This changes the shape of the active site
  • So it is no longer complementary to the substrate and won’t form an enzyme-substrate complex
68
Q

Why might changing certain amino acids in the active site prevent the enzyme functioning ?

Exam question

A
  • This will alter the shape of the active site so enzyme substrate complexes cannot form
  • Amino acids in the active site will be unable to form bonds with the substate
69
Q

Define catabolic reaction

A

break down of complex molecules into simpler products

70
Q

Define anabolic reaction

A

building of more complex molecules from simpler ones

71
Q

Define inhibitor

A

a molecule which binds to something on the enzyme, preventing it from functioning

72
Q

Describe what would happen to rate of reaction if you increased the concentration of a **competitive inhibitor **

What is the impact of increasing substrate concentration ?

A
  • These have the same shape as the substrate
  • So bind to the active site
  • which stops the substrate binding, decreasing rate of reaction
    (inhibitor is not permenently bound so when it leave another molecule can take its place)
    MORE SUBSTRATE = can out complete the inhibitor so rate of reaction will increase
73
Q

What would happen to the rate of reaction if you increased the concentration of a non-competitive inhibitor ?

What is the impact of increasing substrate concentration ?

A
  • Not the same shape as the substrate
  • So they bind to the enzyme away from the active site
  • This causes the active site to change shape
  • so substrate molecules no longer bind, decreasing rate of reaction
    MORE SUBSTRATE = no impact as substrates and inhibitors are not competing for the active site
74
Q

What do DNA and RNA have in common ?

A

They are important information-carrying molecules which are both involved in protein synthesis

75
Q

What is the function of DNA ?

A

holds the genetic information, and codes for the sequence of amino acids in the primary structure of a protein

76
Q

What is the function of RNA ?

A

**transfers genetic information **from DNA to the ribosomes

77
Q

What are the monomers of DNA and RNA ?
What are the components of this structure ?

A

nucleotides which are made from:
* Pentose sugar
* Phosphate group
* Nitrogenous base

78
Q

How are the components in a nuceotide joined ?

A

joined via condensation reactions to form ester bonds, this forms a single nucleotide

79
Q

Describe the components of a DNA nucleotide

A
  • **Deoxyribose **sugar
  • Phosphate group
  • Base (Adenine, Thymine, Cytosine, guanine)
80
Q

Describe the components of an RNA nucleotide

A
  • Ribose sugar
  • Phosphate group
  • Bases (Adenine, uracil, cytosine and guanine)
81
Q

Describe how two nucleotides join, and what type of bond forms ?

A

they join via a condensation reaction between the **deoxyribose sugar and phosphate **forming a polynucleotide
* Forms a phosphodieser bond (Phosphate and two ester bonds)

Phosphodieser bonds are strong and covalent, which ensures the DNA is not broken down

82
Q

What is the sugar-phosphate backbone ?

A

chain of alternating phosphates and pentose sugars, joined by phosphodieser bonds (comprised of two ester bonds and a phosphate)

83
Q

Describe the structure of DNA

A

Double helix made of **two polynucleotide chains **which are ANTIPARALLEL and held by** hydrogen bond**s between complementary base pairs

84
Q

What does antiparallel mean in terms of DNA structure ?

A

Chains run in opposite directions due to the opposite orientation of the sugar molecule (antiparallel - allows the hydrogen bonds to form between complementary base pairs)

  • 5’ and 3’ refers to the carbon no. on the pentose suga, **one strand runs in the 5’ to 3’ direction, the other strand runs in the 3’ to 5’ direction **
  • This makes the DNA more stable and also helps with complementary base pairing
85
Q

How many bonds form between each of the complementary base pairs ?

A

Thymine - Adenine = 2 bonds
Cytosine - Guanine = 3 bonds

86
Q

Describe the structure of an RNA molecule

A
  • single polynucleotide chain
  • much shorter
87
Q

Give 5 ways that the structure of DNA is adapted to its function

A
  • Stable - 3 hydrogen bonds between C-G give it stability (Passed bet. generations without much change) - Base pairs are within the helical structure so are protected
  • Two strands - can seperate during DNA replication, one strand is used as a template
  • Large molecule - lots of genetic info can be stored
  • **Base pairing is complementary **- DNA can replicate and transfer info as mRNA (allows identical copies to be made)
  • **Weak hydrogen bonds **- allows easy separation during DNA replication
88
Q

Why did many scientists doubt that DNA carried the genetic code ?

A

its relative simplicity

89
Q

Why is semi-conservative replication positive in cells ?

A

it ensures genetic continuity

90
Q

Define semi-conservative replication ?

A

each parent strand in the DNA double helix acts as a template for the synthesis of a new, complementary strand.

In the daughter DNA one strand is from the parental DNA and one strand is newly synthesised

91
Q

What is the first stage of DNA replication ?

A

DNA helicase breaks the hydrogen bonds between the complementary base pairs, between the two strands of the double helix
- This causes the double helix to unwind

92
Q

What is the second stage of DNA replication ?

A

-Separated parental strands act as templates
- Free DNA nucleotides are attracted to their complementary base pairs on the template strands

93
Q

What is the third stage of DNA replication ?

A

DNA polymerase catalyses the joining together of** adjacent nucleotides** via a condensation reaction
- This forms phosphodiester bonds and creates the phosphate-sugar backbone

94
Q

Why is DNA helicase important in DNA replication ?

A
  • DNA helicase** breaks the hydrogen bonds** between the two strands in a DNA double helix
  • This creates two template strands which can form** complementary base pairs** with free nucleotides
95
Q

Why is DNA polymerase important in DNA replication ?

A

to join together adjacent nucleotides

96
Q

What word describes the direction of DNA strands, and why does DNA polymerase only move in one direction ?

A

Antiparallel - Strands run in opposite directions, one is 3’ and one is 5’
- The active site of DNA polymerase is only complementary to the 3’ end
- Enzyme moves in a 3’ to 5’ direction, which means the new strand is made in a 5’ to 3’ direction
- As the strands are anti-parallel, polymerase on one template moves in the opposite direction to the other

97
Q

What is the fourth stage of DNA replication ?

A

-Winding enzyme winds the daughter polynucleotides to** form two double helices**
-Two daughter DNA molecules are **genetically identical **to the parent DNA and contain:
* One strand of the parental DNA
* One newly synthesised strand

98
Q

What is the difference between conservative replication and semi-conservative replication ?

A
  • Semi-conservative - One original strand and one newly synthesised DNA strand
  • Conservative - Original DNA remains intact and newly synthesised DNA join together
99
Q

Give the stages of the semi-conservative replication experiment ?

A
  1. Bacteria are grown in heavy nitrogen (Bacteria incorporate the nitrogen isotopes to make nitrogenous bases)
  2. Sample of bacteria from heavy nitrogen is added to** light nitrogen** and left for one round of replication - Sample is taken and spun in centrifuge
  3. DNA is allowed to replicate for two more generations
100
Q

Give the results of meselson and Stahl’s experiment

A
  • First generation -** All DNA contains one strand of heavy and one strand of light** (DNA settles in the middle)
  • Second generation - Some new strands now just contain 14 N
  • Third generation - Most of the strands now just contain 14 N
  • This shows replication is semi-conservative as one parent strand is always conserved and there is always a newly synthesised strand made from only light nitrogen
101
Q

What is ATP ?

A

Adenosine Tri Phosphate
-Immediate source of energy for biological processes (Metabolic reactions must have a constant supply of ATP)

102
Q

Describe the structure of ATP ?

A
  • Ribose (pentose sugar)
  • Adenine nitrogenous base
  • Three inorganic phosphate groups

ATP is a nuceotide derivative

103
Q

How is ATP made ?
What enzyme is the process catalysed by ?

A

-Re-synthesised in a condensation reaction between ADP and Pi
-This occurs during respiration and photosynthesis
-Catalysed by ATP synthase

This does require a small amount of ATP to create the bond

104
Q

How is energy released from ATP ?
What enzyme is the process catalysed by?

A

-ATP is broken down into ADP and P1 in a hydrolysis reaction
-Breaking a bond between the phosphate groups releases a small amount of energy to the surroundings
-Catalysed by ATP hydrolase

  • As only one bond has to be hydrolysed to release energy, ATP is an immediate energy source
105
Q

What two other processes is ATP hydrolysis useful for ?

Give some examples of where they occur

A
  • Can be coupled with other energy requiring reactions so energy released can be used directly instead of being lost
  • Inorganic phosphate released can be bonded to another compound (Phosphorylation) which makes the compound more reactive

  • Hydrolysis is coupled with muscle contraction and active transport (both require energy)
    -Phosphorylation happens to glucose at the start of respiration (glycolysis)
106
Q

Give the five properties of ATP which make it a better source of immediate energy in cells compared to glucose

A
  • ATP releases energy in a small amount - means less is wasted and cells don’t overheat
  • Only **one bond has to be hydrolysed **to energy release is immediate - Glucose needs several bonds to be broken
  • ATP is small and soluble - can easily be transported around the cell to provide energy (This one is the same as glucose)
  • ATP can transfer energy to another molecule - transferring one of its phosphate groups
  • ** ATP cannot leave the cell** - the cell always has its own supply of ATP (glucose can leave so the cell can run out)
107
Q

In what two places is ATP synthesised ?

A

mitochondria and chloroplasts

108
Q

Give four places where ATP is used ?

A
  • Activation of molecules - Phosphorylation lowers the activation energy
  • **Metabolism **- building macromolecules (starch and polypeptides)
  • Movement - muscle contraction
  • Active transport - changes the shape of carrier proteins in plasma membranes, allowing the movement of molecules against the concentration gradient
    * Secretion - formation of lysomes
109
Q

Describe the** structure of water**

A

-Water is a dipolar molecule
-It is electrically neutral but the charge is uneavenly distributed due to the fast the oxygen atom is slightly negative and the** hydrogen is slightly positive**
-This means hydrogen bonds can form between the oxygen and hydrogen of neighbouring molecules

110
Q

Give some examples of when water is used as a metabolite

A

-Breaks down complex molecules in hydrolysis
-One of the raw materials in photosynthesis

111
Q

Why does water make a good solvent ?
Give some examples

A

Dipolar **
-Slight positive charge** will attract any negative ions in solutes, and slight negative charge will attract any positive ions
(These molecules that dissolve are polar - charged, water cannot dissolve non-polar molecules)
-This means the compound is fully surrounded so can be split up and dissolved

112
Q

Why does water have a** high specific heat capacity ?**
Why is this useful ?
Give some examples

A

-There are many** hydrogen bonds can absorb a lot of energy so a lot more energy is needed to separate them** (So lots of energy is needed to raise the temperature)
- Useful as itstemperature remains relatively stable ** (acts as a buffer against temperature changes in the environment)
- Uses: a suitable habitat for aquatic organisms, and the water inside organisms helps them maintain a constant internal body temperature **- means enzymes will not denature

113
Q

Why does water have a** high latent heat of vaporisation ?**
Why is this useful ?
Give some examples

A
  • Many** hydrogen bonds** which need a** lot of energy to break** and convert water from its liquid state to a gaseous state
  • Means water provides a cooling effect
  • Uses: When humans sweat large amounts of heat energy from the skin is tranferred to the water to evaporate it, which removes lots of heat and **cools **the organism
    (similar impact during transpiration in plants)
114
Q

Why does water have strong cohesion ?
Why is this useful/give examples here?

A
  • Water molecules are dipolar, and the hydrogen bonds cause them to stick together
  • Allows** columns of water to move up the xylem **- easier to draw up a column than individual molecules
  • Provides surface tension to water - allows small organisms to move and live on water
115
Q

What are inorganic ions ?

A

* No carbon
* Occur in solutions in the cytoplasm and bodily fluids
* Concentrations can fluctuate

116
Q

What is the function of iron ions ?

A
  • They can bind to oxygen so are a key component in haemoglobin
117
Q

What is the function of hydrogen ions?

A
  • Concentration determines pH
  • This is important for enzyme activity as changes in PH can impact the tertiary structure of the protein
118
Q

What is the function of** sodium ions** ?

A
  • Used for the** transport of glucose and amino acids **across cell membranes (Co-transport)
  • Also needed for** transmission of nerve impulses**
119
Q

What is the function of phosphate ions ?

A
  1. Attach to other molecules to form** phosphate groups (Part of RNA, DNA)**
  2. Bonds between phosphate groups store energy in ATP
  3. Found in phospholipids (Bilayer in cell membranes

Biology Paper 1 (15 decks)

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