Comprehensive Biology, Chemistry, and Physics Lecture Review

A comprehensive set of practice flashcards covering cell biology, biochemistry, microbiology, genetics, immunology, inorganic chemistry, physical chemistry, and classical physics based on the provided lecture transcript.

What are the three principles of cell theory?

1. All living things are made up of one or more cells. 2. Cells are the most basic unit of structure and function in all living things. 3. All cells are created by pre-existing cells.

What is the function of the mitochondria in eukaryotic cells?

Respiration producing adenosine triphosphate ($ATP$).

Which organelle is responsible for protein synthesis and translation?

Ribosomes.

What is the specific role of the Golgi apparatus and Golgi vesicles?

Packaging of proteins for transport.

What are the three specific plant organelles mentioned and their functions?

1. Chloroplasts: site of photosynthesis. 2. Large permanent vacuole: maintains cell pressure and stores substances. 3. Cell wall: provides structure, support, and protection.

How does the cell wall of a prokaryotic cell differ from a plant cell?

Prokaryotic cell walls contain murein/peptidoglycan (a glycoprotein) rather than cellulose.

What is the basic structure of an amino acid?

Amino acids contain an amine group ($NH_2$), a carboxyl group ($COOH$), and a side chain represented by $R$.

How are dipeptides and polypeptides formed?

Dipeptides are formed by the condensation of 2 amino acids via peptide bonds; polypeptides are formed by the condensation of many amino acids.

What are the common monosaccharides and what do they form?

Glucose, galactose, and fructose are common monosaccharides that form larger carbohydrates (disaccharides and polysaccharides).

What is the main role of phospholipids in living organisms?

Their main role is in plasma membranes to provide flexibility and transport mechanisms through a bilayer structure.

How do surface area and volume ratio affect exchange systems?

The surface area must be large compared to the volume for efficient exchange; if the ratio is small, specialised transport mechanisms are required to maximise diffusion.

What are the components of a DNA nucleotide?

Deoxyribose (a pentose sugar), a phosphate group, and one of four organic bases: adenine, cytosine, guanine, or thymine.

How does an RNA molecule differ from a DNA molecule in terms of structure?

RNA is a relatively short single-stranded polynucleotide chain containing ribose sugar and uracil ($U$) instead of thymine.

What are the roles of DNA helicase and DNA polymerase in semi-conservative replication?

DNA helicase unwinds the double helix and breaks hydrogen bonds; DNA polymerase builds the new strand by using the original chain as a template.

What is the difference between genetics and genomics?

Genetics focuses on the functioning and composition of single genes; genomics focuses on the entire genetic material (coding and non-coding DNA) of an organism.

Identify the classification and size of viruses.

Acellular, no organelles, obligate intracellular parasites, approximately $20$ to $300\,\text{nm}$.

What is the formula for calculating magnification?

$$\text{magnification} = \frac{\text{size of image}}{\text{size of object}}$$

What are the four levels of protein structure?

1. Primary: amino acid sequence. 2. Secondary: hydrogen bonds forming $\alpha$-helices and $\beta$-sheets. 3. Tertiary: $R$ group interactions creating 3D shape. 4. Quaternary: multiple polypeptide chains combined.

What are the three types of bonds that stabilise the tertiary structure of proteins?

Hydrogen bonds, ionic bonds, and disulfide bridges (covalent bonds between cysteine groups).

What does it mean for the genetic code to be 'degenerate'?

It means that each amino acid can be coded for by more than one codon (sequence of 3 DNA bases).

Contrast the outcomes of mitosis and meiosis.

Mitosis produces 2 genetically identical diploid daughter cells for growth and repair; meiosis produces 4 genetically different haploid gametes for reproduction.

What is the process of 'crossing over' in meiosis and its significance?

Homologous chromosomes exchange segments of genetic material in meiosis I, creating genetic variation.

What is the chemical equation for aerobic respiration?

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$ (producing $ATP$).

Define a pathogen.

A biological agent that causes illness or disease by damaging host tissues and/or by producing toxins.

How does the immune system differentiate between 'self' and 'non-self'?

Through antigens, which are surface molecules acting as chemical markers; the system tolerates 'self' antigens and triggers a response to 'non-self' antigens.

What is the difference between cell-mediated and antibody-mediated immunity?

Cell-mediated immunity involves T lymphocytes destroying pathogens without antibodies; antibody-mediated immunity involves B lymphocytes producing specific antibodies.

Why are transition metals used differently than Group 1 metals?

Transition metals are stronger, harder, denser, have higher melting points, and are less reactive with water and oxygen compared to Group 1 metals.

What is the difference between strong and weak acids in aqueous solution?

Strong acids (like hydrochloric acid) completely dissociate; weak acids (like ethanoic acid) only partially dissociate.

What are the three principles of collision theory?

1. Molecules must collide. 2. Molecules must collide with enough activation energy. 3. Molecules must be in the correct spatial orientation.

What is the function of a catalyst in a chemical reaction?

It increases the rate of reaction by providing an alternative pathway with a lower activation energy without being permanently changed.

How is the Rf value calculated in chromatography?

$$Rf = \frac{\text{distance travelled by the substance}}{\text{distance travelled by the solvent}}$$

State Ohm's Law and the units used.

$V = IR$, where $V$ is potential difference (Volts), $I$ is current (Amperes), and $R$ is resistance (Ohms).

What are the characteristics of mains electricity in the United Kingdom?

Alternating current ($AC$), $230\,\text{V}$, and a frequency of $50\,\text{Hz}$.

Define longitudinal and transverse waves.

Longitudinal waves move in the same direction as the vibrating particles; transverse waves move at right angles to the direction of vibration.

Compare Alpha, Beta, and Gamma radiation in terms of ionising and penetrating power.

Alpha: high ionising/low penetrating. Beta: medium ionising/medium penetrating. Gamma: low ionising/high penetrating.

Match the following SI units: Electric current, Temperature, and Amount of substance.

Electric current: ampere ($A$); Temperature: Kelvin ($K$); Amount of substance: mole ($mol$).

State the three Gas Laws provided in the notes.

Boyle's Law: $P_1V_1 = P_2V_2$; Charles's Law: $\frac{V_1}{T_1} = \frac{V_2}{T_2}$; Gay-Lussac's Law: $\frac{P_1}{T_1} = \frac{P_2}{T_2}$.

Contrast Newtonian and non-Newtonian fluids.

Newtonian fluid viscosity remains constant as applied force changes; non-Newtonian fluid viscosity changes as applied force changes.