2.2- Biological molocules Flashcards
What type of bond is water called?
Covalent
How is a hydrogen bond formed?
Oxygen molecules pull electrons closer,making it slightly negative. This makes hydrogen atoms slightly positive which forms hydrogen bonds.
On diagrams, how should you express charge?
with a delta+ or delta- symbol
Why is water so important in the human body? (name 3)
It acts as a medium for chemical reactions
It is a major component for tissues
It maintains body temperature
Why is water so important for plants? (name 3)
It is required for photosynthesis
it is used to transport substances such as nutrients
It can act as a habitat for organisms such as algae
What is water surface tension?
The property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of the water
Why is water surface tension important for organisms?
It allows small organisms to walk on water and lily pads to float.
What is special about waters SHC?
It has a very high SHC because of the many hydrogen bonds which require lots of energy to break.
This means water is a liquid at RT instead of a gas
Why is waters high SHC important for organisms?
It ensures the body temperature remains largely constant
When we sweat, water absorbs heat before evaporating which helps cool us down and regulates temperature
Why does water behave as a solvent?
The hydrogen bonds attract other molecules such as salt which can make water heavily attracted to the other molecule and break it apart/dissolve it
Why is it important for organisms that water behaves as a solvent?
it allows substances to be dissolved and transported to different parts of an organism
Why is water a dense liquid?
the hydrogen bonds pull the water molocules closer together
Why is the density of water important for organism?
Waters density means that many animals can float or swim
organisms can also change their density to float/sink
What is another word for water concentration?
Water potential
What are carbohydrates?
Organic compounds which compose of carbon, hydrogen and oxygen atoms only
Why are carbohydrates essential to organisms?
Because they act as energy sources, energy stores and structural unit
What is the general formula for monosaccharides.
CnH2nOn
What are isomers?
a compound with the same formula but a different arrangement of atoms
What are the 2 isomers that glucose exists in?
Alpha glucose and Beta glucose
True or false. Monosaccharide can be joined together to form disaccharides.
true
What is a reaction called if water is removed?
condensation reaction
What is a reaction called if water and enzymes are added to break apart a bond?
Hydrolysis reaction
If 2 monosaccharides are bonded together, what is this bond called?
1-4 glycosidic bond
Why is an a1-4 glycosidic bond called this?
it is a bond between the first carbon atom and the 4th carbon atom
Why are glycogen and starch suitable energy stores?
they are compact and are found in chains which can be easily snipped off for respiration by hydrolysis reactions
Why are branched chains better for releasing lots of energy quickly?
more molecules can be “snipped off” by hydrolysis at once which provides more energy
Why are polysaccharides less soluble in water than monosaccharides?
They have a large size and because regions which could hydrogen bond with water are hidden on the inside of the molecule
True or False. Amylose and Amylopectin are found in animals
False. Amylose and Amylopectin are found in plants
Were are Amylose and Amylopectin stored in the organism?
Dense granules in starch grains in cells
What disaccharide is formed when 2 alpha glucose molocules are joined together?
maltose
What disaccharide is formed when alpha glucose and fructose join together?
Sucrose
What disaccharide is formed when alpha/beta glucose and galactose join together?
Lactose
What polysaccharide is formed when many alpha glucose molecules join together?
Amylose
Briefly describe the structure of Amylose.
A long unbranched chain of alpha glucose.
The angles of the glycosidic bond give it a coiled structure.
This makes it compact and great for storage.
Briefly describe the structure of Amylopectin.
Long branched chains of alpha Glucose.
Its side branches allow the enzymes that break molecules down to get at the bonds easily so glucose can be released quickly.
Starch is the main energy storage material in……..
Plants
Starch is a mixture of the 2 polysaccharides……….
Amylose and amylopectin
Glycogen is the main energy storage material in……
Animals
Briefly describe the structure of glycogen.
A long branched chain of alpha glucose with loads of side branches which allow glucose to be released very quickly
It is also a compact molecule and good for storage
Briefly describe the structure of Cellulose.
Long unbranched chains of beta glucose.
When beta molecules bond, they form straight cellulose chains.
Every other beta glucose molecule is rotated 180 degrees to allow them to bond together.
Why do hydrogen bonds make cellulose strong?
Cellulose chains are linked together by hydrogen bonds to form strong fibres called microfibrills.
These strong fibres provide structural support for cells
What are the 3 types of Lipids?
Triglycerides
Phospholipids
Cholesterol
What are triglycerides
Macromolocules (Complex molocules with a relatively large molecular mass) which contain the elements carbon, hydrogen and a little bit of oxygen. They have 1 molecule of glycerol and 3 fatty acids attached to them.
What is the structure of triglycerides?
1 molocule of glycerol and 3 fatty acids
Why are lipids insoluble in water?
Fatty acid molecules have long tails made up of hydrocarbons.
These tails are hydrophobic and repel water Molocules which make lipids insoluble in water.
What type of bonds to triglycerides contain?
Ester bonds
The process in which triglycerides are synthesised is called…
esterification
Hydrolysis reactions ………… bonds.
Break
Condensation reactions …………… bonds
create
What is a lipid?
A group of substances containing a large amount of carbon and hydrogen that are soluble in alcohol instead of water because they are non polar molocules
What are the 5 main functions of triglycerides?
energy source energy store insulation buoyancy protection
What is the strucure of a saturated fatty acid?
no C=C double bonds and as many hydrogens as possible
What is the structure of an unsaturated fatty acid?
at least 1 C=C double bond and as a result, fewer hydrogen atoms
What can ester bonds form between?
each glycerol molecule and up to 3 fatty acids
What is a phospholipid?
A glycerol molocule bonded to 2 fatty acids and 1 phosphate group
Where are phospholipids found?
Cell membranes
A Phospholipid bilayer
How do phospholipids form barriers that water soluble molocules cant pass across?
The phospate group is on the head of the molocule and is hydrophillic so dissolves on the outside of the bilayer
The fatty acid tails are hydrophobic so form a barrier that water soluble molocules cant pass across
What is an AA?
The building blocks of all proteins
What is a dipeptide?
2AA’s joined together by a peptide bond
What is a polypeptide?
a long polymer chain of 2 or more AA’s joined together by peptide bonds
The general structure of all AA’s involves 1 central atom bonding to 4 groups. What are these groups?
Hydrogen Group
Carboxyl Group
Amino Group
R group
Which amino acid group changes the amino acid formed?
The R group. There are 20 different types of R groups meaning there are 20 different AA’s
Peptide bonds are formed in ………… reactions between………….?
Condensation
Amino Acids
Peptide bonds occur between groups?
Carboxyl group of 1 atom and Hydroxyl group of another
When peptide bonds are broken apart, this is a ………… reaction?
Hydrolysis
How many different levels of protein structure are there?
What are they called?
4
Primary, Secondary, Tertiary, Quaternary
What is found on the primary structure of proteins?
An amino Acid sequence
What is found on the secondary structure of proteins?
Coiling or folding of amino acid chains to produce alpha helices, beta pleated sheets or unstructured regions.
What is found on the tertiary structure of proteins?
The folding of alpha helices, beta pleated sheets or unstructured regions to form an overall 3d shape
What is found on the Quaternary structure of proteins?
NOT always applicable
How multiple polypeptide chains are arranged to make a protein
How are secondary structure proteins held together?
By hydrogen bonding
How are tertiary structure proteins held together?
Hydrogen bonds
Ionic bonds
Disulfide bonds
Hydrophobic and Hydrophillic interactions
Secondary structure proteins are susceptible to…?
PH and temperature changes
Quaternary structures are held together by…?
Hydrogen bonds
Ionic bonds
Disulfide bonds
Hydrophobic and hydrophillic interactions
Do turtles have fingernails?
YES
