Biological Molecules Flashcards
What are proteins composed of
Long chains of amino acids
How many differnt amino acids are there in a protein
20
What do all amino acids contain
Carbon, hydrogen, oxygen, nitrogen and some container sulphur
Do all amino acids have the same structure?
Yes
Check you know the structure
(Card one)
What AreThe amino acids in a protein chain are attached to each other by ?
Strong peptide bonds
Can amino acids be arranged in any sequence
Yes
How many amino acids can be in a protein
Up to several hundred
The —— of the amino acid in a protein determines its structure
Order
What does the structure of a protein determin
How it works
T or F
Each protein has its own special shape
T
What is a primary structure
(Proteins)
The order in which the amino acids are arranged in a protein chain
What is the secondary structure of a protein
Some chains coil up or fold into pleats that are held together by weak forces of chemical attraction called hydrogen bonds.
What are tertiary structure proteins
(Especially enzymes)
The coiled chain of amino acids is folded into a ball that’s held together by a mixture of weak chemical bonds (eg, hydrogen bonds and stronger bonds eg. Disulfide bonds)
What is it called if a protein has a roughly spherical shape
Globular proteins
Example of a globular protein
Enzymes
How many elements does carbohydrates contain
3
What elements do carbohydrates contain
Carbon
Hydrogen
Oxygen
Examples of carbohydrates
Sugars
Starch
Cellulose
What are sugars
Small, water soluble molecules that taste sweet
What 2 groups are sugars divided into
Monosaccharides
And
Disaccharides
What are monosaccharides
The single units from which all the other carbohydrates are built
Examples of monosaccharides
Glucose and fructose
What are the 2 forms of glucose
Alpha and beta
What are disaccharides
They are formed when 2 monosaccharides are joined together by a chemical reaction
A water is also formed
(So is called a condensation reaction)
Glucose + glucose —>
Maltose (a disaccharide) + water
Glucose + fructose —> sucrose (a disaccharide) + water
What are polysaccharides
Polymers (large molecules made up of monomers)
What are the monomers of polysaccharides
Monosaccharides
What 2 differnt polysaccharides is starch molecules made up of
Amylose and amylopectin
(Which are polymers of glucose)
What are amylose amd amylopectin
Polymers of glucose
They are insoluble, compact starch molecules that make them an ideal way of storing glucose
T or F
Starch is only found in plant cells
T
What is cellulose
A polysaccharide
It is a polymer of glucose ( alike starch but the bonding is differnt between the glucose units)
What are cellulose molecules arranged like
Long and straight
Several cellulose molecules can lie side by side to from what?
Microfibrils
What are molecules held together by in microfibrils
Many weak hydrogen bonds
T or f
Cellulose is found in both plant and animal cells
F
What do microfibrils do
Strengthen plant cells walls
What do lipids contain
Carbon
Hydrogen
Oxygen
What are lipids (ex)
Oils
Fats
Plant oils and animal fats are mostly made up of a group of lipids called?
Triglycerides
A triglyceride consist of what?
A molecule of glycerol with 3 fatty acids attached to it
What is a fatty acid molecule
A long chain of carbon atoms with an acidic group (-COOH) on one end.
Hydrogen atoms are attached to carbon atoms
What do we say in a fatty acid molecule if every carbon atom in the chain is joined by a single bond
Saturated
What do we say in a fatty acid molecule if one or more bond is a double bond.
Unsaturated
A fatty acid with many double bonds is called what?
Polyunsaturated
What are phospholipids
A special type of lipid that have 2 fatty acid chains and a phosphate group and a glycerol
What are cell membranes made from
A double lay of phospholipids
What are enzymes
Help speed up biochemical reactions
(Biological catalysis)
They increase the rate of reactions
Thousands of biochemical reactions take place every second, what is the sum of these reactions called
Metabolism
What is a metabolic pathway
A single chain of biochemical reactions
How do enzymes act as catalysts
Enzymes reduce the activation energy
What determines how an enzymes works
The order of amino acids determines its structure so determines how it works
Examples of what enzymes are involved in
Breaking sown molecules (such as digestive enzymes )
Building up molecules (such as DNA replication )
What is a substrate
A substance that’s acted upon by an enzyme
What is the active site
A region on the surface of the enzyme molecule where a substrate molecule can attach itself. It’s where the catalysed reaction takes place.
the shape of the substrate molecule and the chase of the active site are — ——?
Complementary
Once the enzyme-substrate complex has formed what is released
Products
T or f
Enzymes catalyse many reactions
F
They usually only catalyse one specific chemical reaction
Why do enzymes only catalyse one specific reaction
The substrate molecules must be the correct shape to fit the active site
Only one substrate will be the correct shape to fit
What will happen to the enzyme if the active site is changed
It will affect how well the enzyme works
How does temp. Effect enzyme activity
As temp inc. enzyme reactions become faster because the molecules have more energy
What happens if temp. Becomes too high for enzymes
The atoms of the enzyme molecules vibrate more rapidly and break the weak bonds that hold the tertiary structure together .
The shape of the active site changes and the substrate can no longer fit.
The enzyme is said to be denatured
Aside from temp, what else can denature enzymes
Acids and alkalis
How can too strong acids and alkalis affect enzyme activity
Hydrogen ions in acids and hydroxyl ions in alkalis can disrupt weak bonds and change the shape of the active site
