Test 1 Flashcards
What are the four key biomolecules, and their percentage in a cell?
Water - 70%
Proteins – 18%
Carbohydrates – 4%
Lipids – 3%
Nucleic acids – 1.35%
what are carbohydrates main function, their monomers, the bond that holds the monomers together, their elements and an example
Primary source of energy.
Monomers: monosaccharides
Bond: Glycosidic bond
Elements: C,H,O
Ex: Starch
what are lipids main function, their monomers, the bond that holds the monomers together, their elements and an example
Secondary source of energy, insulation
Monomers: Fatty acids and glycerol
Bond: Ester bond
Elements: C,H,O
Ex: Fats
what are protein main function, their monomers, the bond that holds the monomers together, their elements and an example
Protein:
Structural and functional units of the human body
Monomers: Amino acids
Bond: Peptide bond
Elements: CHONS
Ex: Collagen
what are nucleic acids main function, their monomers, the bond that holds the monomers together, their elements and an example
Nucleic acids:
Stores genetic information
Monomers: Nucleotides
Bond: Phosphodiester bonds
Elements:CHONP
Ex: DNA and RNA
What is the function of enzymes
Enzymes are biological catalysts which increase the rate of chemical reactions. Lower activation energy. They are proteins.
The term biochemistry was first coined by….. in….
Carl neuburg in 1903
What is metabolism?
All biochemical reactions that occur in living organisms in order to maintain life.
What are vitamins
Co-enzymes needed to help the body utilize essential nutrients
Briefly describe the 4 stages of protein structure
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
what is Catabolic pathway and an example
Release energy by breaking down complex molecules into simpler compounds.
Example is cellular respiration, the breakdown of glucose in the presence of oxygen.
what is Anabolic pathways and an example
Consume energy to build complex molecules from simpler molecules.
Example is synthesis of protein from amino acids.
Why is Protein hydrolysis important in protein metabolism?
Or protein denaturation
pH: influences protonation of charged side groups, hydrolysis of peptide bonds
Temperature: disrupts H-bonding through increased molecular vibration (become ‘sticky’ and aggregate)
list the digestive enzymes that break down biomolecules
Carbohydrates: amylase, sucrase,
maltase, lactase
Lipids: lipase
Protein: pepsin, protease-trypsin, peptidase.
what is a cofactor
Are nonprotein enzyme helpers, Zn++
what is a coenzyme
Are organic cofactors, ATP
potential cofactor question: what does a cofactor do
without a cofactor attached to the protein, it is not active. When the cofactor attaches, then the protein becomes active and substrates can bind.
what is the enzymatic reaction depending on temp
Low temp – decreased flexibility of enzyme structure (rigid)
High temp – intermolecular interactions disrupted, and enzyme denatures
Nucleic acids are associated with which biomolecule?
protein
what is the lock and key model and the induced fit model
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.
what are inhibitors
Enzyme inhibitors are molecules that bind to an enzyme to prevent it from functioning optimally. Thus, they reduce the rate of reaction.
What are the types of enzyme inhibitors and regulators
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
how much ATP do cells have.
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.
Where does glycolysis happen and why
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.
what is glycolysis
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.
It is important to ensure that your diet is adequately rich in vitamins because:
Most vitamins are co-enzymes needed to help the body utilize essential nutrients
Define biochemistry reactions
Cells continually carrying out thousands of chemical reactions linked together in pathways in order to maintain life.
Define Metabolism and its importance.
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.
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?
Her body will use alternative energy stores such as fats, and work in anaerobic conditions.
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?
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.
peptide bond is what type of bond
covalent
List and briefly describe 6 functions of proteins in the human body.
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.
What is Proteome?
A proteome is the entire complement of proteins that is or can be expressed by a cell, tissue, or organism.
Compare human Proteome vs Genome?
Genome = entire set of genes in the genome of a cell.
Proteome = entire set of proteins produced by the cell.
Why there are at least 250 different proteomes in the human body?
There are at least 250 different proteomes to correspond for the 250 cell types in the body.
What are key components of an amino acid structure? How many common amino acids are there?
- Central carbon atom
- Amino group (amino)
- Carboxyl group (acid)
- Single hydrogen
- Variable R group – side chain
Properties of amino acid determined by R-group
who many common amino acids are there
20
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.
All chemical breakdown processes in cells directly involve
reactions that are controlled by catalysts
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?
Its activity would slow down.
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:
biological catalysts
Describe why only one enzyme is specific for one substrate.
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.
how do enzymes function
Enzymes function as biological catalysts that speed up the rate of reaction by reducing the activation energy.
