Test 1

Question 1

What are the four key biomolecules, and their percentage in a cell?

Answer 1

Water - 70%
Proteins – 18%
Carbohydrates – 4%
Lipids – 3%
Nucleic acids – 1.35%

Question 2

what are carbohydrates main function, their monomers, the bond that holds the monomers together, their elements and an example

Answer 2

Primary source of energy.
Monomers: monosaccharides
Bond: Glycosidic bond
Elements: C,H,O
Ex: Starch

Question 3

what are lipids main function, their monomers, the bond that holds the monomers together, their elements and an example

Answer 3

Secondary source of energy, insulation
Monomers: Fatty acids and glycerol
Bond: Ester bond
Elements: C,H,O
Ex: Fats

Question 4

what are protein main function, their monomers, the bond that holds the monomers together, their elements and an example

Answer 4

Protein:
Structural and functional units of the human body
Monomers: Amino acids
Bond: Peptide bond
Elements: CHONS
Ex: Collagen

Question 5

what are nucleic acids main function, their monomers, the bond that holds the monomers together, their elements and an example

Answer 5

Nucleic acids:
Stores genetic information
Monomers: Nucleotides
Bond: Phosphodiester bonds
Elements:CHONP
Ex: DNA and RNA

Question 6

What is the function of enzymes

Answer 6

Enzymes are biological catalysts which increase the rate of chemical reactions. Lower activation energy. They are proteins.

Question 7

The term biochemistry was first coined by….. in….

Answer 7

Carl neuburg in 1903

Question 8

What is metabolism?

Answer 8

All biochemical reactions that occur in living organisms in order to maintain life.

Question 9

What are vitamins

Answer 9

Co-enzymes needed to help the body utilize essential nutrients

Question 10

Briefly describe the 4 stages of protein structure

Answer 10

Primary structure: Refers to the linear amino acid sequence in a polypeptide chain in direction of N-terminus to C-terminus.
Secondary structure: second order of structure resulting in a-helix and b-pleated sheets
Tertiary structure: folding and packing resulting in a single polypeptide chain
Quaternary structure: multiple polypeptide chain complexes

Question 11

what is Catabolic pathway and an example

Answer 11

Release energy by breaking down complex molecules into simpler compounds.
Example is cellular respiration, the breakdown of glucose in the presence of oxygen.

Question 12

what is Anabolic pathways and an example

Answer 12

Consume energy to build complex molecules from simpler molecules.
Example is synthesis of protein from amino acids.

Question 13

Why is Protein hydrolysis important in protein metabolism?
Or protein denaturation

Answer 13

pH: influences protonation of charged side groups, hydrolysis of peptide bonds
Temperature: disrupts H-bonding through increased molecular vibration (become ‘sticky’ and aggregate)

Question 14

list the digestive enzymes that break down biomolecules

Answer 14

Carbohydrates: amylase, sucrase,
maltase, lactase
Lipids: lipase
Protein: pepsin, protease-trypsin, peptidase.

Question 15

what is a cofactor

Answer 15

Are nonprotein enzyme helpers, Zn++

Question 16

what is a coenzyme

Answer 16

Are organic cofactors, ATP

Question 17

potential cofactor question: what does a cofactor do

Answer 17

without a cofactor attached to the protein, it is not active. When the cofactor attaches, then the protein becomes active and substrates can bind.

Question 18

what is the enzymatic reaction depending on temp

Answer 18

Low temp – decreased flexibility of enzyme structure (rigid)
High temp – intermolecular interactions disrupted, and enzyme denatures

Question 19

Nucleic acids are associated with which biomolecule?

Answer 19

protein

Question 20

what is the lock and key model and the induced fit model

Answer 20

lock and key: in the lock and key mechanism, it assumes that the active site of an enzyme is rigid in shape and the substrate fits into the active site without the site changing.
The induced fit model assumes that the active site changes its shape to conform to the substrates shape which allows the enzyme and substrate to bind.

Question 21

what are inhibitors

Answer 21

Enzyme inhibitors are molecules that bind to an enzyme to prevent it from functioning optimally. Thus, they reduce the rate of reaction.

Question 22

What are the types of enzyme inhibitors and regulators

Answer 22

Competitive inhibitors
Competitive inhibitor binds to active site so that the substrate is directly blocked and cannot bind to the active site.

Non-competitive (allosteric) inhibitors
Allosteric inhibitor binds to an allosteric site which changes the shape of the enzymes active site so that the substrate cannot bind.’

Positive allosteric regulators
Helps enzyme work better: promotes and stabilises an active conformation

Question 23

how much ATP do cells have.

Answer 23

Cells have approx. 1 sec supply of ATP, so it is not stored.
Must be constantly generated, in 1 sec, 10 million ATP produced in a single cell.

Question 24

Where does glycolysis happen and why

Answer 24

Outside of the mitochondria (in the cytoplasm)
Glucose is too large to go through the mitochondria membrane so that is why it happens outside of the cell.

Question 25

what is glycolysis

Answer 25

Glycolysis is the process where a glucose molecule is broken down into pyruvate molecules. This generates a small amount of ATP (2 molecules)

It also creates NADH, which carry energy to be used later in cellular respiration.

This process happens in the cell’s cytoplasm.

Question 26

It is important to ensure that your diet is adequately rich in vitamins because:

Answer 26

Most vitamins are co-enzymes needed to help the body utilize essential nutrients

Question 27

Define biochemistry reactions

Answer 27

Cells continually carrying out thousands of chemical reactions linked together in pathways in order to maintain life.

Question 28

Define Metabolism and its importance.

Answer 28

Metabolism refers to the collection of all chemical reactions occurring within a cell. Normal metabolism is vital for health, growth, reproduction and survival of human beings.

Question 29

If a runner’s levels of oxygen and glucose are depleted during a race, what will her body do to produce the energy she needs?

Answer 29

Her body will use alternative energy stores such as fats, and work in anaerobic conditions.

Question 30

David is following a very low fat training regime. What is one symptom that he may experience if he does not allow some carbohydrate into his diet? Why would this symptom emerge?

Answer 30

High fatigue levels as his body would not have enough carbohydrates, resulting in low availability of ATP as it is used as a primary source of energy.

Question 31

peptide bond is what type of bond

Answer 31

covalent

Question 32

List and briefly describe 6 functions of proteins in the human body.

Answer 32

Support – proteins provide structural support for individual cells and our body
Defence - globular proteins called immunoglobulins (antibodies) seek out foreign material.
Transport – proteins located on the cell membrane allow substances to enter and exit cells.
Motion - Myosin and actin protein arrange to form muscle fibres for motion.
Regulation – protein hormones that control and regulate our body function.
Storage – proteins that store irons and gases, etc.

Question 33

What is Proteome?

Answer 33

A proteome is the entire complement of proteins that is or can be expressed by a cell, tissue, or organism.

Question 34

Compare human Proteome vs Genome?

Answer 34

Genome = entire set of genes in the genome of a cell.
Proteome = entire set of proteins produced by the cell.

Question 35

Why there are at least 250 different proteomes in the human body?

Answer 35

There are at least 250 different proteomes to correspond for the 250 cell types in the body.

Question 36

What are key components of an amino acid structure? How many common amino acids are there?

Answer 36

• Central carbon atom
• Amino group (amino)
• Carboxyl group (acid)
• Single hydrogen
• Variable R group – side chain

Properties of amino acid determined by R-group

Question 37

who many common amino acids are there

Answer 37

20

Question 38

Describe the digestion and absorption of proteins, beginning in the mouth.

Include the types of digestion involved at each organ and state which enzymes or chemicals (if any) are involved at each organ, and the end molecules and how they are absorbed.

Question 39

All chemical breakdown processes in cells directly involve

Answer 39

reactions that are controlled by catalysts

Question 40

Meat tenderizer contains an enzyme that interacts with meat. If meat is coated with tenderizer and then placed in a refrigerator for a short time, how would the enzyme be affected?

Answer 40

Its activity would slow down.

Question 41

Plants such as the Venus flytrap produce chemical compounds that break down insects into substances that are usable by the plant. The chemical compounds that break down the insects are most likely to be:

Answer 41

biological catalysts

Question 42

Describe why only one enzyme is specific for one substrate.

Answer 42

The substrate is complementary to the active site. Enzymes can only catalyse one kind of substrate. This means the enzymes will only operate on very specific substrates.

Question 43

how do enzymes function

Answer 43

Enzymes function as biological catalysts that speed up the rate of reaction by reducing the activation energy.