MODULE 1: Chapter 1.2 Flashcards
What is biochemistry?
An interdisciplinary science that integrates concepts from chemistry, cell biology, and physiology
Biochemistry is crucial for understanding molecular life science.
What are the four major types of biomolecules?
- Amino acids
- Nucleotides
- Simple sugars
- Fatty acids
These biomolecules form the basis of life.
What forms macromolecules?
Higher-order structures of biomolecules
Macromolecules include proteins, nucleic acids, and polysaccharides.
What are triacylglycerols?
Lipid macromolecules formed by covalent linkage of three fatty acids to glycerol
Triacylglycerols are important for energy storage.
What enables cells to coordinate complex biochemical processes?
Metabolic pathways
Examples include glycolysis, the citrate cycle, and fatty acid metabolism.
What is cell specialization?
The ability of multicellular organisms to exploit their environment through communication between cells
This involves signal transduction mechanisms.
What six elements make up more than 97% of the weight of most organisms?
- Hydrogen
- Oxygen
- Carbon
- Nitrogen
- Phosphorus
- Sulfur
Most of this mass comes from hydrogen and oxygen, primarily as water (H2O).
What are trace elements required for life?
- Zinc
- Iron
- Manganese
- Copper
- Cobalt
These elements primarily function as cofactors in proteins.
What are the essential ions for life?
- Calcium
- Chloride
- Magnesium
- Potassium
- Sodium
These ions play key roles in cell signaling and neurophysiology.
What is a covalent bond?
A bond formed when two atoms share unpaired electrons in their outer shells
The strength of a covalent bond depends on electronegativities, distance, and nuclear charge.
What is organic chemistry?
The study of carbon-based compounds
Organic molecules contain carbon and are fundamental to biological systems.
What are the six most abundant functional groups in biomolecules?
- Amino (R─NH3⁺)
- Hydroxyl (R─OH)
- Sulfhydryl (R─SH)
- Phosphoryl (R─PO3²⁻)
- Carboxyl (R─COO⁻)
- Methyl (R─CH3)
These groups significantly influence the chemical properties of biomolecules.
What is the primary function of amino acids?
Building blocks for proteins
They are linked into polypeptides to form proteins.
What are the components of nucleotides?
- Nitrogenous base
- Five-membered sugar (ribose or deoxyribose)
- One to three phosphate groups
Nucleotides are essential for DNA and RNA formation.
What does ATP stand for and its function?
Adenosine triphosphate; it serves as the energy currency of the cell
ATP transfers phosphate groups to provide energy for reactions.
What are simple sugars also known as?
Monosaccharides or disaccharides
They have an empirical formula of CH2O.
Fill in the blank: The most common carbon bonds in biomolecules are _______.
C─C, C═C, C─H, C─N, C─S, C─O, C═O
These bonds determine the structure and function of organic molecules.
True or False: Rotation does not occur around carbon-carbon double bonds.
True
Atoms are largely fixed in position relative to each other in double bonds.
What is the significance of the octet rule in covalent bonding?
Atoms seek to have eight electrons in their outer shell for stability
Hydrogen requires two electrons, while other elements like O, N, and C require eight.
What is the empirical formula of simple sugars?
CH2O
This formula reflects the 2:1 ratio of hydrogen to oxygen atoms, similar to water.
What are simple sugars also known as?
Monosaccharides or disaccharides
The term ‘saccharide’ is derived from the Latin word for sugar, ‘saccharum’.
What is glucose’s role in living cells?
Involved in energy conversion reactions, cell signaling, and cell structure
Glucose (C6H12O6) is a key monosaccharide.
What is the structural component of plant cell walls?
Cellulose
Glucose is the building block for cellulose.
What is glycogen’s function in animals?
Energy storage form of carbohydrate
Glycogen is primarily stored in liver and muscle tissues.
What type of bond links fatty acids to glycerol in triacylglycerols?
Ester bond
Triacylglycerols consist of three fatty acid esters covalently linked to glycerol.
What are the two types of fatty acids based on saturation?
Saturated and polyunsaturated fatty acids
Saturated fatty acids contain no double bonds, while polyunsaturated fatty acids contain multiple double bonds.
What is the most abundant type of lipid in cell membranes?
Phospholipids
Phospholipids consist of a simple organic molecule, a phosphoryl group, and two fatty acids.
What is the primary carbohydrate component in the exoskeletons of insects?
Chitin
Chitin consists of N-acetylglucosamine units linked by β(14) glycosidic bonds.
What are the two most abundant polymers in cells?
Nucleic acids and proteins
Nucleic acids consist of linked nucleotides, while proteins consist of linked amino acids.
What determines the polarity of DNA polymers?
Distinct 5′-phosphoryl and 3′-hydroxyl groups
This polarity allows for the storage of information in the sequential arrangement of nucleotides.
How many different octamer polypeptides can theoretically be assembled from 20 amino acids?
2.56 × 10^10
The theoretical number of octamer sequences is much larger than the actual number encountered biologically.
What type of bond links amino acids in proteins?
Peptide bond
Peptide bonds are covalent bonds that link amino acids in a polypeptide chain.
What is the difference between α(14) and β(14) glycosidic bonds?
Structural differences that require different enzymes for hydrolysis
Humans can digest amylose with α(14) bonds but lack the enzyme to digest cellulose with β(14) bonds.
What are metabolic pathways?
Linked biochemical reactions necessary for life-sustaining processes
Metabolic pathways consist of reactants and products that are interdependent and regulated.
What is the role of ATP in polymer synthesis?
ATP provides energy for the assembly of macromolecules
High ATP levels favor synthesis, while low ATP levels favor degradation.
What are the two types of pathways in metabolism?
Anabolic and catabolic pathways
Anabolic pathways synthesize macromolecules, while catabolic pathways break them down.
What is systems biology?
A discipline that describes complex chemical reaction networks in cells
It uses mathematical models to reflect metabolic flux in response to conditions.
What is an example of a mini-pathway in the urea cycle?
The conversion of citrulline and aspartate to arginine and fumarate
Argininosuccinate serves as both a product and reactant in this pathway.
What is Argininosuccinate?
The product of the first reaction and the reactant for the second reaction in the urea cycle.
Argininosuccinate is formed from citrulline and aspartate.
Which enzymes function in the mini-pathway converting citrulline and aspartate into arginine and fumarate?
Argininosuccinate synthetase and argininosuccinase.
These enzymes facilitate the reactions in the urea cycle.
What are the three common types of metabolic pathways?
- Linear pathways
- Forked pathways
- Cyclic pathways
Each type has distinct characteristics regarding product formation and reactant usage.
What is the primary role of ATP hydrolysis in metabolic reactions?
To drive reactions toward product formation, often making them essentially irreversible.
ATP hydrolysis provides the energy necessary for many biochemical reactions.
How do prokaryotic and eukaryotic cells differ in size?
Eukaryotic cells are about 10–100 times larger than most bacteria.
Prokaryotic cells are typically around 1 µm in diameter.
What is chromatin?
Eukaryotic DNA packaged with proteins, forming a structure contained within the nucleus.
Chromatin plays a key role in gene regulation and DNA packaging.
What are the functions of mitochondria?
Responsible for many metabolic reactions involved in energy conversion and production of ATP.
Mitochondria are often referred to as the powerhouse of the cell.
What do chloroplasts do in plant cells?
Convert light energy into chemical energy through photosynthesis.
This process is vital for plant energy production and growth.
What is the endosymbiotic theory?
The theory that eukaryotic cells evolved from large predatory cells engulfing aerobic bacteria, which became mitochondria.
This theory explains the origin of complex cells and their organelles.
What is signal transduction?
The process by which cells communicate with one another in response to environmental changes using ligands and receptors.
This process is crucial for coordinating cellular responses in multicellular organisms.
What role do ligands play in signal transduction?
Ligands bind to receptors, causing conformational changes that affect intracellular activity.
Common ligands include metabolites and hormones.
True or False: Eukaryotic cells have a rigid cell wall.
False.
Animal cells lack a rigid cell wall, allowing for shape alteration.
What is the primary function of the circulatory system in animals?
To transport biomolecules, including signaling molecules and metabolic fuels, throughout the organism.
This system is vital for maintaining homeostasis and supporting metabolic processes.
Fill in the blank: The _______ contains ribosomal RNA and protein and is where ribosomes are assembled.
nucleolus
The nucleolus is a substructure within the nucleus of eukaryotic cells.
What are plasmids?
Circular DNA molecules in bacteria that replicate independently of the bacterial chromosome.
Plasmids often encode genes for antibiotic resistance.
What is the structure that maintains the shape of eukaryotic cells?
Cytoskeleton
The cytoskeleton is a network of protein filaments that provides structural support.
Which organelles are involved in degradation and detoxification of macromolecules?
- Lysosomes
- Peroxisomes
These organelles play critical roles in cellular waste management.
What is the diameter of typical bacterial cells?
About 1 µm (10−6 meter).
This small size allows for efficient nutrient uptake and metabolic processes.
What is required for aerobic metabolism and discharges waste gas?
Oxygen
Oxygen is essential for aerobic cellular respiration, where it helps convert glucose into energy while producing carbon dioxide as a waste product.
What are signal transduction pathways?
Mechanisms that coordinate cellular responses within tissues
These pathways often involve the binding of ligands to receptors, initiating cellular responses.
What do the top rung on the hierarchical ladder of life describe?
Complex interactions among organisms within ecosystems
These interactions can have beneficial or detrimental effects on local or global ecosystems.
What can algal blooms lead to in aquatic environments?
Biochemical imbalance and oxygen depletion
This can result in massive fish kills, particularly in warm water with minimal circulation.
What are harmful algal blooms stimulated by?
Increased nutrient levels, optimal water temperatures, and sunlight exposure
These changes can occur naturally or from industrial discharges of nitrogen or phosphates.
What is glucose classified as in the chemical hierarchy of life?
A biomolecule containing carbon, oxygen, and hydrogen
It serves as a primary energy source and is involved in various metabolic pathways.
What are the primary components of plant cell walls?
Cellulose, a polymer of glucose
Glucose can also be stored in the form of starch in plants and glycogen in animals.
What is a biomolecule?
An organic compound essential to living organisms
Major types include amino acids, nucleotides, simple sugars, and fatty acids.
Define macromolecule.
An organic polymer with high molecular mass
Examples include proteins, nucleic acids, and polysaccharides.
What is a metabolic pathway?
Sequences of biochemical reactions coordinated by a cell
These pathways respond to available energy and other cellular signals.
What is an ecosystem?
A geographic community where organisms share resources in a linked system
This includes energy flows and nutrient cycles among different organisms.
What is the function of amino acids?
Building blocks for proteins and precursors to nitrogen-containing biomolecules
They play critical roles in various biological processes.
What is a protein?
A polymer of amino acids
Proteins are essential for numerous cellular functions and structures.
What is a nucleotide?
An organic molecule consisting of a base, sugar, and phosphate groups
Nucleotides are the building blocks of nucleic acids like DNA and RNA.
What is deoxyribonucleic acid (DNA)?
A polymeric macromolecule encoding inheritable genetic information
DNA consists of nucleotides linked through phosphodiester bonds.
True or False: Ribosomes are involved in protein synthesis.
True
Ribosomes are large RNA-protein complexes that facilitate the assembly of amino acids into proteins.
What is the function of mitochondria?
Responsible for energy conversion and ATP production
Mitochondria are often referred to as the powerhouse of the cell.
What does the endosymbiotic theory propose?
Eukaryotic cells evolved from engulfed aerobic bacteria
This theory suggests that mitochondria and chloroplasts originated from symbiotic relationships.
What is a phospholipid?
Lipids containing a phosphate group and two fatty acids
Phospholipids are key components of cell membranes.
What is the role of the Golgi apparatus in eukaryotic cells?
Facilitates protein translocation and secretion
It modifies proteins and prepares them for their final destinations.
What is a vacuole?
A membrane-bound organelle that stores metabolites
Vacuoles also isolate harmful molecules in plant cells.
Fill in the blank: A _______ is a small molecule that binds to target proteins.
[ligand]
Ligands influence the structure and function of proteins to control biochemical processes.
