Lectures 1 & 2 Flashcards
What is meant by health?
a state of complete physical, mental and social well-being
What is meant by disease?
any deviation from the normal structural or functional health state of an individual
What is meant by patient?
individuals who seek medical care, treatment, or attention from healthcare professionals, including pharmacists, due to a disease, condition, injury, or a health-related concern.”
What are the features of a red blood cell?
*Biconcave shape
* No nucleus
* Contain haemoglobin
* Small and flexible
What are the features of neurons?
- Thin and long cells
- Branched at their ends
- Different subcellular parts
- Release of neurotransmitter signals
What are the levels of organisation in the human body?
he levels of increasing complexity are: Cell → Tissue → Organ → Organ System → Organism
What are the two main types of cells?
Prokaryotic cells (bacteria) and eukaryotic cells (e.g. human cells). Prokaryotic cells lack a nucleus and organelles, while eukaryotic cells have a nucleus and membrane-enclosed organelles
What are the four major organic macromolecules in cells?
Carbohydrates/polysaccharides, proteins, lipids, and nucleic acids. These are polymers made of specific repeating molecular units called monomers
What are the basic components found in all cells?
Plasma membrane, cytosol, ribosomes, genome (DNA), and biological macromolecules
What is anabolism?
Cells link monomers together to form a polymer
through polymerisation/condensation reactions
(requiring energy)
What is catabolism?
Polymers are broken down into smaller molecules
by hydrolysis (realising energy)
what is metabolism?
catabolism + anabolism reactions
What does the cytoplasm do In prokaryotes?
Internal content of the cell - site of many reactions
Ribosome function in prokaryotes?
▪ Composed of a large (50S) and a small subunit (30S)
▪ Each subunit is made of rRNA and proteins
▪ Involved in protein synthesis, translating mRNA code
Bacterial DNA chromosome in prokaryotes?
▪ Dispersed in a central cytoplasmic space - Nucleoid
▪ Single circular DNA - not linked to histone proteins
Inclusion bodies in prokaryotes?
Aggregates of reserve material (Storing function)
Plasmids in Prokaryotes?
Confer new ability, such as degradative ability of antibiotics = drug resistance
Plasma membrane in prokaryotes? (internal surface layer)
Flexible lipid bilayer, as in eukaryotic cells (with no sterols).
Controls the movement of molecules (nutrients/waste)
sometimes, site of reactions (respiration/photosynthesis
Cell wall in prokaryotes?(middle surface layer)
Rigid structure to preserve cell shape & integrity
Glycocalyx in prokaryotes? (outer surface layer)
Polysaccharides layer: Capsule (organised and stable) or Slime layer (loosely attached)
Protection against dehydration, immune system (phagocytosis) and antibiotics
Adherence factor
Flagellum in prokaryotes?
Long and whip-like appendages
Used for cell motility (movement).
It is also a sensory structure to detect nutrients
Fimbria/Pili in prokaryotes?
Short and thin projections
Used for attachment to a surface or other cells
Sex pili in prokaryotes?
Rigid hair-like tubular structures (longer than fimbriae)
Use to facilitate genetic material transfer between two bacteria (through the conjugation
process)
Cytoplasm in Eukaryotes?
Content inside the plasma membrane (covered in Lec. 7) excluding the nucleus
* Highly organised and dynamic
* It includes:
cytosol
* gel-like fluid (pH 7.2) to support organelles
* It includes ribosomes, cytoskeleton, enzymes, etc
* It is the site of many cellular activities:
Protein synthesis (Lec. 4) and degradation
Metabolic reactions (e.g. glycolysis)
Cell signalling pathways (Lec. 8)
distinct cell organelles
* enclosed by membranes (separated by the cytosol)
Ribsosomes in eukaryotic cells?
Function: Cell machinery for protein synthesis (translation step – Lec. 4)
Structure:
* Made by 2 subunits: large (60S) & small (40S) forming 80S
bigger than the prokaryotic ones (50s and 30S 70S)
Types: Free floating in the cytosol or bound to the rough endoplasmic reticulum
Both subunits are combinations of :
Ribosomal proteins +
ribosomal RNA (rRNAs)
S refers to their sedimentation coefficients (indirect size measure)
Cytoskeleton in Eukaryotes?
A network of protein filaments and tubules that provides structural support
Functions:
Structural support: cell shape & resists mechanical stress
Intracellular transport: facilitates movement of
organelles, vesicles, and molecules
Regulates cellular processes (eg cell division & motality
Structures - Composition
* 3 types of filamentous protein polymers (long repetitions of 1 or more proteins):
Microfilaments (7 nm in diameter),
Intermediate filaments (10 nm in diameter)
Microtubules (25 nm in diameter)
What is the structure and major functions of microfilaments in the cytoskeleton?
STRUCTURE:
* Long, thread-like filaments of 2 helical strands of actin
protein repetitions - (7nm in ⌀)
MAJOR FUNCTIONS:
Depending on interaction with actin binding proteins (e.g. myosin).
Very dynamic- Rapid assembly and disassembly for quick rearrangements
Muscle contraction
Assist with cell movement
Support cell’s shape (e.g. microvilli in intestinal cells)
Cell division: formation of contractile ring in cytokinesis
What is the structure and functions of the cytoskeletons intermediate filaments?
STRUCTURE
* Rope-like fibres formed by many long strands of several
types of proteins (e.g. keratin) twisted together - (10nm in ⌀)
MAJOR FUNCTIONS
Provide mechanical strength and stability to cells and
tissues (abundant in muscle cells)
Anchor cells in extracellular matrix
No effect in cell motility (not bound to motor proteins). More stable
What is the structure and functions of the cytoskeletons microtubules?
STRUCTURE
* Long and rigid hollow cylinders made by repetitions of two
tubulin protein subunits (α & β) - (25nm in ⌀)
MAJOR FUNCTIONS
Cell structural support
Intracellular transport (linked to motor proteins, e.g. kinesin, dynein)
Generate force and cell movement (cilia and flagella)
Cell divisions forming Centrioles DNA segregation
What can cytoskeleton defects lead to?
Cytoskeleton defects can lead to cardiomyopathies, cancer, etc.
* Some anti-cancer drugs interfere with microtubule formation to block
the uncontrolled cancer cell divisions.
