Podcast
Questions and Answers
What determines the chemical bonding properties of an atom?
What determines the chemical bonding properties of an atom?
- The number of neutrons in the atom.
- The number of orbitals surrounding the atom.
- The number of protons in the atom.
- The distribution of electrons and their charges. (correct)
Which of the following best describes the role of electrons in chemical bonding?
Which of the following best describes the role of electrons in chemical bonding?
- Electrons determine the atomic number of an element.
- Electrons are only involved in forming covalent bonds.
- Electrons are responsible for the mass of an atom.
- Electrons are involved in the formation of both ionic and covalent bonds. (correct)
What is the defining characteristic of an isotope?
What is the defining characteristic of an isotope?
- An isotope has a different number of neutrons compared to its original element. (correct)
- An isotope has a different number of electrons compared to its original element.
- An isotope has a larger atomic mass compared to its original element.
- An isotope has a different number of protons compared to its original element.
What is the primary factor that governs the movement of electrons between atomic shells?
What is the primary factor that governs the movement of electrons between atomic shells?
Which of the following elements would be considered essential for life as discussed in the text?
Which of the following elements would be considered essential for life as discussed in the text?
Atoms are most stable when they have...
Atoms are most stable when they have...
What is the significance of the term 'universal solvent' when applied to water?
What is the significance of the term 'universal solvent' when applied to water?
Which type of bond is characterized by the sharing of electrons between atoms?
Which type of bond is characterized by the sharing of electrons between atoms?
What is the primary type of bond responsible for determining the structure of proteins?
What is the primary type of bond responsible for determining the structure of proteins?
How does the presence of isotopes impact the field of carbon dating?
How does the presence of isotopes impact the field of carbon dating?
The text mentions 'membranes'. What is the fundamental function of these biological membranes?
The text mentions 'membranes'. What is the fundamental function of these biological membranes?
Which type of bond is formed by the interaction between partial charges on polar molecules?
Which type of bond is formed by the interaction between partial charges on polar molecules?
Water's ability to act as a universal solvent is primarily due to:
Water's ability to act as a universal solvent is primarily due to:
The high specific heat of water is a result of...
The high specific heat of water is a result of...
Cohesive and adhesive properties of water are primarily attributed to:
Cohesive and adhesive properties of water are primarily attributed to:
The polarity of water contributes to its ability to interact with which of the following types of compounds?
The polarity of water contributes to its ability to interact with which of the following types of compounds?
Which of the following organelles is NOT part of the endomembrane system?
Which of the following organelles is NOT part of the endomembrane system?
What is the purpose of using GFP in plant cells?
What is the purpose of using GFP in plant cells?
What is the role of SYP121 in the cell?
What is the role of SYP121 in the cell?
What happens when GFP is co-transfected with SYP121ΔC in leaves?
What happens when GFP is co-transfected with SYP121ΔC in leaves?
What technique is used to visualize the dynamic movement of organelles in the cell?
What technique is used to visualize the dynamic movement of organelles in the cell?
What is the role of the Golgi apparatus in the cell?
What is the role of the Golgi apparatus in the cell?
Which of the following organelles are NOT enclosed by a membrane?
Which of the following organelles are NOT enclosed by a membrane?
What is the process called when proteins move from the endoplasmic reticulum (ER) to the Golgi apparatus?
What is the process called when proteins move from the endoplasmic reticulum (ER) to the Golgi apparatus?
What is the primary function of membranes in cells?
What is the primary function of membranes in cells?
What is the main reason why sucrose diffusion across membranes is very slow?
What is the main reason why sucrose diffusion across membranes is very slow?
What is the term used to describe molecules like phospholipids that have both hydrophilic and hydrophobic regions?
What is the term used to describe molecules like phospholipids that have both hydrophilic and hydrophobic regions?
What is the Nernst Equation used to calculate?
What is the Nernst Equation used to calculate?
What is the primary driving force for the diffusion of ions across a membrane?
What is the primary driving force for the diffusion of ions across a membrane?
How does the biological membrane contribute to cellular energy generation?
How does the biological membrane contribute to cellular energy generation?
What is the significance of voltage across cell membranes?
What is the significance of voltage across cell membranes?
How can the voltage across endomembranes be measured?
How can the voltage across endomembranes be measured?
Flashcards
Atoms
Atoms
Atoms are the smallest particles that retain the properties of an element.
Sub-atomic particles
Sub-atomic particles
Components of atoms: protons, neutrons, and electrons.
Atomic number
Atomic number
Determined by the number of protons in an atom.
Isotopes
Isotopes
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Chemical bonding
Chemical bonding
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Electron distribution
Electron distribution
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Energy and electron movement
Energy and electron movement
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Membranes
Membranes
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Bonds
Bonds
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Ionic Bonds
Ionic Bonds
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Covalent Bonds
Covalent Bonds
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Valence Electrons
Valence Electrons
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Hydrogen Bonds
Hydrogen Bonds
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Polarity of Water
Polarity of Water
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Capillary Action
Capillary Action
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Hydration Shells
Hydration Shells
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Amphipathic molecules
Amphipathic molecules
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Phosphatidyl choline
Phosphatidyl choline
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Compartmentalization
Compartmentalization
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Nernst Equation
Nernst Equation
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Ion gradients
Ion gradients
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Diffusion rates
Diffusion rates
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Bioenergetics
Bioenergetics
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Eukaryotic Organelles
Eukaryotic Organelles
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Mitochondria
Mitochondria
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Chloroplasts
Chloroplasts
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Golgi Apparatus
Golgi Apparatus
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Endoplasmic Reticulum (ER)
Endoplasmic Reticulum (ER)
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Green Fluorescent Protein (GFP)
Green Fluorescent Protein (GFP)
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Endocytosis
Endocytosis
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Exocytosis
Exocytosis
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Study Notes
Hands-On Summer-Break Research
- The Dobbie Smith Prizes offer a £1000 bursary for a 6-8 week summer research experience.
- Open to first-year natural sciences and related studies students at the University of Glasgow.
- Students must consult with a suitable member of staff, agree on a project, and then submit an application letter to the Undergraduate School.
- Details are available on the MOODLE site or from Prof. M. Blatt ([email protected]).
- The deadline for applications is 12:00 noon on Friday, 28th March 2025.
Atoms, Bonds, Water, and Membranes
- What are atoms?
- Atoms are the smallest particles that retain the properties of an element (e.g., carbon, oxygen).
- Atoms are made up of subatomic particles: protons, neutrons, and electrons.
- Elemental properties are determined by the atomic number (number of protons).
- Most atoms have equal numbers of protons and neutrons, but some isotopes may have additional neutrons (e.g., carbon-14).
- What are bonds?
- Bonds form when atoms share or exchange electrons to achieve more stable (full) electron shells.
- Different bonds (ionic, covalent) form depending on how atoms transfer or share electrons.
- Why is water a 'universal solvent'?
- Water is a polar molecule (due to uneven electron distribution), meaning it has partial charges.
- This polarity allows water to interact with other polar and charged molecules.
- What are membranes?
- Membranes are phospholipid polymers (made of fatty acids, glycerol, phosphate, and a terminal group).
- Phospholipids are amphipathic molecules, meaning they have both hydrophilic and hydrophobic parts. This leads to spontaneously assembling monolayers and bilayers in water.
- Membranes are crucial for compartmentalization within cells, protecting components, and enabling signal transduction.
What Determines Chemical Bonding?
- The physical chemistry of an atom is determined by its electronic complement and the distribution of electrons around the nucleus.
- Electrons are arranged in electron shells and orbitals, which define the probability distribution of that electron within shells and orbitals.
- Electrons can move between shells, requiring an input or release of energy.
What Determines Bond Formation?
- Bonds form when atoms share or exchange electrons to achieve stable or filled electron shells.
- Stable atomic states possess paired electrons and filled electron shells.
- Atoms with unpaired electrons or partially-filled outer shells react to fill or empty their shells.
- Examples are given using the Lewis-dot representation.
Electron Shells Define the Periodic Table of Elements
- Electron shells determine an elements position on the Periodic Table.
- Elements with similar electron configurations share similar chemical properties and reactivity.
Which Bonds are Important for Life?
- Ionic Bonds:
- Form when atoms exchange electrons.
- Result in oppositely charged ions that attract each other forming an ionic bond, like in sodium chloride.
- Crucial in biological processes, such as forming crystals and for transporting ions within the cell.
- Atomic valence differs from ionic valence.
- Covalent Bonds:
- Form when atoms share electrons.
- Examples are given, including hydrogen, water, and methane.
- Different covalent bond types (single, double, triple bonds) are defined by the number of electrons shared.
- Hydrogen Bonds:
- Partial charge interactions between polar molecules.
- Important for interactions between water molecules.
- Van der Waals Interactions:
- Interactions that arise between atoms with locally induced dipoles, very close together.
Why is Water a 'Universal Solvent' for Life?
- Water molecules are polar; they possess a partial positive charge on hydrogen, and a partial negative charge on oxygen.
- These interactions allow water to readily dissolve polar (charged) and ionic compounds, creating hydration shells around them.
- This high polarity and tendency to form hydrogen bonds also explains water's cohesive and adhesive properties, high specific heat, and role as a good insulator.
Adhesive/Cohesive Forces in Wetting and Capillary Action
- Cohesion refers to the attraction between water molecules.
- Adhesion refers to the attraction between water molecules and other molecules.
- These forces are crucial for water transport and plant transpiration.
- Cohesive tension limits tree size due to how water moves upward through the stem
Biological Membranes Hold Charge
- Diffusion of Ions:
- Driven by chemical and electrical gradients.
- Selective Diffusion:
- Across semi-permeable membranes creates a small ion imbalance.
- The Nernst Equation:
- Describes the equilibrium between chemical & electrostatic forces on charged molecules (ions).
- Electrode Use:
- Microelectrodes can be used to measure membrane voltage.
Organelles and Their Locations
- A variety of organelles is present to separate different roles and protect various components, and include:
- Nucleus
- Rough endoplasmic Reticulum
- Smooth endoplasmic Reticulum
- Golgi
- Mitochondria
- Chloroplasts
- Lysosomes
- These organelles are membrane-bound and contribute to both structural and functional compartmentalization.
What Are Membranes?
- Membranes are phospholipid bilayers.
- Phospholipids are amphipathic (hydrophilic head, hydrophobic tails).
- These molecules spontaneously form monolayers and bilayers in water.
- Simple detergents function as amphipathic molecules and are able to dissolve other polar and organic compounds in water.
Why Are Membranes Important?
- Membranes compartmentalize metabolic activities.
- Membranes separate and protect cellular components.
- Membranes provide a scaffold for signalling components.
- Membranes act as a medium for cellular energy generation (e.g., electron transport chain).
- Diffusion across membranes is important for transporting molecules between the inside and outside of cells.
What Do Diffusion Rates Mean?
- Diffusion rates across membranes are influenced by factors like distance, concentration gradients, and the size of the diffusing molecules.
- Diffusion is slower in thicker membranes than thinner ones.
- Limits cell & membrane size in biological materials.
Fluorescence - A New Window on the Cell
- Fluorescence occurs when a molecule absorbs light, causing electrons to move to an excited state.
- Energy is then released when the electrons return to their ground state, resulting in the emission of light at a longer wavelength.
- This enables cell analysis and is used to investigate details of cell structure and function
Green Fluorescent Protein (GFP)
- GFP is a protein that fluoresces when exposed to light.
- Genetically engineered GFP can be used to visualize cell processes and structures in plants and animals.
Endoplasmic Reticulum
- ER is a network of membranes within cells involved in protein synthesis and processing and other tasks. This network is highly mobile within the cell.
- ER is interconnected by membranes.
Golgi
- Golgi is organized in stacks and/or networks of membrane sacs that process, modify, and transport proteins.
- Similar to ER, the Golgi also appears to be highly mobile within the cell.
- Both plant and animal cells have similar Golgi structures.
Chloroplasts
- Chloroplast are plant organelles that carry out photosynthesis.
- Chloroplasts and mitochondria have double membranes, suggesting a symbiotic origin.
- Chloroplasts have their own independent division and replication mechanisms.
- Chloroplasts can communicate within cells by creating structures called Stromules.
Membrane Structure and Function
- Membranes are phospholipid polymers that spontaneously form monolayers and/or bilayers in water.
- Membranes function as physical barriers and support structures within the cell.
- Organelles, including ER, Golgi, mitochondria and chloroplasts are membrane-enclosed compartments crucial for eukaryotic cell function.
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