Mason Bennett

Amino Acids Structure

This flashcard set helps with memorizing the names of standard amino acids by matching each to its full name. Ideal for students studying biochemistry or molecular biology.

Algebra 1 - Unit 10 Review

This set of flashcards introduces key concepts related to square root and cube root functions, radical expressions, and equations. It covers definitions, transformations, and methods for solving radical equations using examples.

Microbiology Practical 3

This flashcard set reviews the major fungal phyla—Chytridiomycota, Mucoromycota, Ascomycota, and Basidiomycota—focusing on their habitat, reproductive strategies (sexual and asexual), and defining structures like zoospores, asci, conidia, and basidiospores. Great for mycology and fungal taxonomy studies.

Microbiology: Mycotoxicosis

Moist, warm environments and stressed or rotting feed (especially protein-rich) promote fungal growth. Mycotoxins are produced during rapid fungal growth.

The Circulatory System

Blood doesn’t accumulate in arterioles because capillaries are far more numerous, giving a much greater total cross-sectional area. The aorta shows greater blood pressure fluctuation due to its proximity to the heart and presence of elastic tissue for stretch and recoil. Water from tissue fluid returns to the blood via osmosis, driven by a water potential gradient created by plasma proteins, or via the lymphatic system.

10: Species and Taxonomy

A species is a group capable of producing fertile offspring. Courtship behaviours ensure successful mating by helping organisms recognise suitable partners and synchronise reproduction. The binomial naming system uses genus and species names, while organisms are classified using taxonomic ranks from domain down to family.

9: Genetic diversity and adaptation

Mutations are changes in the DNA base sequence or quantity, potentially forming new alleles. A substitution mutation replaces one base with another, which may alter a single amino acid in a protein. This can change the protein’s structure and function, especially if the affected amino acid is crucial to the protein’s tertiary structure.

8: DNA, genes and protein synthesis

This deck covers key concepts related to DNA, genes, and protein synthesis, including the structure and function of genetic material, the process of transcription and translation, and the genetic code.

7: Mass Transport

Haemoglobin transports oxygen by binding it in the lungs and releasing it in tissues. Its quaternary structure includes four polypeptide chains and haem groups with iron ions. DNA differences lead to variations in haemoglobin structure and oxygen affinity, which affects how efficiently oxygen is picked up and released.

6: Gas Exchange in Insects and Fish

Specialised exchange surfaces, such as insect tracheal systems and fish gills, are adapted for efficient gas exchange with features like a large surface area, short diffusion pathways, and mechanisms to maintain diffusion gradients. Insects reduce water loss with waterproof exoskeletons and spiracles, while fish use gill filaments and lamellae to maximise oxygen absorption from water.

5.7: The human immunodeficiency virus

HIV consists of a lipid envelope, attachment proteins, a capsid, RNA, and reverse transcriptase. It infects T-helper cells by converting its RNA into DNA and integrating into the host genome. It replicates using host machinery, damaging the immune system. Over time, the loss of T-helper cells leads to AIDS, where the immune system is too weak to fight infections.

5.6: Vaccination

Immunity can be passive—where antibodies are introduced from an external source—or active, where the body produces its own antibodies after exposure to antigens. Vaccination involves introducing antigens (often from inactive pathogens) to stimulate the immune system, providing long-term protection by generating memory cells.

5.5: Antibodies

Antibodies are proteins produced by B cells that bind specifically to antigens, forming antigen-antibody complexes. Their structure includes variable and constant regions, allowing them to agglutinate pathogens and mark them for destruction. Monoclonal antibodies, engineered for medical use, can target cancer cells but raise ethical concerns due to animal testing and potential side effects.

5.4: B-lymphocytes and humoral immunity

B cells are central to humoral immunity, producing specific antibodies in response to antigens. Through clonal selection, they divide and form plasma cells for rapid antibody production and memory cells for long-term immunity. This enables a faster, stronger secondary response upon re-infection, helping prevent illness.

5.3: T-lymphocytes and cell-mediated immunity

Antigens are molecules on cell surfaces that trigger immune responses when recognized as foreign. T lymphocytes (cell-mediated immunity) mature in the thymus and detect infected or abnormal cells by recognizing these antigens, while B lymphocytes (humoral immunity) mature in bone marrow. T cells are activated when phagocytes or infected cells present antigens on their surface.

5.1: Cell Recognition and The Immune System

This deck covers key concepts related to cell recognition and the immune system, including definitions of pathogens, defense mechanisms, and lymphocyte function.

4.4: Active Transport

Active transport moves molecules against a concentration gradient using ATP and carrier proteins, unlike passive processes like facilitated diffusion, which move substances along the gradient without energy. Both involve specific carrier proteins, but only active transport requires metabolic energy and works against concentration differences.

4.3: Osmosis

Osmosis is the passive movement of water from high to low water potential through a selectively permeable membrane. It’s affected by solute concentration, and placing cells in hypertonic, hypotonic, or isotonic solutions alters their water content. Water potential in potato cells can be investigated using a sucrose dilution experiment and analysed via percentage mass change and calibration curves.

4.2: Diffusion

Diffusion is the passive movement of molecules from a high to low concentration until equilibrium is reached. Factors like concentration gradient, surface area, and diffusion distance affect its rate. Facilitated diffusion involves specific protein channels and carrier proteins that help transport larger or charged molecules across the membrane without using energy.

4.1: Structure of the cell-surface membrane

The phospholipid bilayer forms the basis of cell membranes, with hydrophilic heads facing outward and hydrophobic tails inward, creating a selective barrier. It allows lipid-soluble substances to pass, prevents water-soluble substances from crossing, and provides flexibility. Internal membranes compartmentalize cellular activities and support metabolic functions.