Module 1 + 2: Introduction / Cell Biology Flashcards
What are the levels of organisation?
From smallers to largest:
Atoms
Molecules
Cells
Tissues
Organs
Organ Systems
Organisms
Populations
Ecosystem
Biosphere
Name the ten organ systems
Circulatory
Digestive
Endocrine
Immune
Integumentary
Musculoskeletal
Nervous
Reproductive
Respiratory
Urinary
Difference between Function and Process? What are their approaches called?
Function explains the “why” -Teleological approach. Process (or mechanism) describes the “how” -Mechanistic approach.
What law does homoeostasis depend on?
The law of mass balance.
What is the law of mass balance?
Mass Balance = Existing body load + Intake or metabolic production - Excretion or metabolic removal.
Difference between local and reflex control?
Local control is restricted to tissue, reflex control uses long-distance pathways or a nervous and/or endocrine system.
What are the four biomolecules?
Carbohydrates
Lipids
Proteins
Nucleotides
What does a nucleotide consist of?
One or more phosphate groups, a 5-carbon sugar and a carbon-nitrogen ring
What is a carbon-nitrogen ring structure called?
A nitrogenous base
(Advanced Question) What is an eicosanoid?
Eiconsanoids are a modified 20-carbon fatty acid with a complete or partial carbon ring at one end and two long carbon chain “tails”. They act as regulators of physiological functions.
What bond links two DNA nitrogenous bases?
Hydrogen bonds
What bases are purines and pyrimidines?
Purines: -Adenine -Guanine Pyrimidines -Cytosine -Thymine -Uracil
(Advanced Question) When a protein is selective bonded, what type of bond is it?
Non-covalent
What are signalling molecules also called?
Ligands
What are the three types of protein activation and two types of protein inhibition called?
Proteolytic activation
Cofactors
Allosteric activator A
Competitive inhibitor
Allosteric inhibition
What is proteolytic activation?
Protein is inactive until peptide fragments are removed.
What are cofactors in regards to protein activation?
Cofactors are required for an inactive protein to be active; attaches are the active binding site.
What is allosteric activation?
An allosteric activator is a modulator that binds to protein away from the binding site and turns it on.
What is a competitive inhibition?
A competitive inhibitor blocks ligands by binding at the binding site.
What is allosteric inhibition?
An allosteric inhibitor is a modulator that binds to protein away from the binding site and in-activates the binding site.
Three major cavities of the body?
Cranial
Thoracic
Abdominopelvic
What are the three major fluid-filled compartments of the body?
Circulatory system
Eyes
Cerebrospinal fluid
What is a lumen?
A channel or a tube; usually connects with outside environment.
Four main types of hollow organs?
Heart
Lungs
Blood vessels
Intestines
What are the four major components of the cytoskeleton?
Microvilli
Micro-filaments
Micro-tubules
Intermediate filaments
What are micro-filaments? (Advanced Question) What are they composed of?
Micro-filaments form a network just inside the cell membrane. Composed of actin.
What are micro-tubules? (Advanced Question) What are they composed of?
Composed from the globular protein tubulin; these are the largest cytoskeleton fibre.
What are intermediate filaments? (Advanced Question) What are two major examples?
They are named intermediate filaments because they are intermediate in thickness between actin filaments and micro-tubules. Examples are myosin and keratin .
What do centrosomes do?
Assemble tubulin monomers into microtubules.
What do centrioles do?
Direct DNA movement in cell division.
What do cilia do?
Assist with fluid movement across cells.
What are kinesins and dyneins do on microtubules?
Protein bases that assist with movement of vesicles along microtubules .
What do dyneins do?
Support the base and assist with movement of cilia and flagella.
(Advanced Question) What are the two components of the mitochondria? What is the space between them called?
There is an ECM matrix and an inner matrix and folds into leaflets called cristae. The inter-membrane space lies between the two.
(Advanced Question) What is the Golgi apparatus composed of?
A series of hollow curved sacs called cristenae stacked on top of one another. The GA participates in protein modification and packaging.
Difference between smooth and rough ER?
Rough ER has ribosomes; it is the main site of protein synthesis while the smooth ER synthesis lipids and in some cells concentrates and stores calcium ions.
What is the nucleus surrounded by?
A double-membrane nuclear envelope.
What protein is usually found alongside DNA and RNA in the nucleus?
Nucleoli
How does a nucleus contact with the cytoplasm?
Through pores
What are lysosomes?
Lysosomes are small, spherical storage vesicles that contain powerful digestive enzymes
What are peroxisomes?
Peroxisomes contain enzymes that break down fatty acids and some foreign materials.
What layer of matrix does most epithelial attach to?
The basal lamina
Three type of cell junctions?
Gap Junctions (communicating junction) Tight Junction (occluding junction) Desmosomes (anchoring junction)
Where do desmosome junctions anchor? What do desmosomes allow?
They anchor in the cytoskeleton. Since they space out two cells, they allow water and fluid to flow between the two cells (like a bridge).
What do gap junctions function like? Where are you most likely to find them?
A tunnel between two cells. Most likely found in cells that spread action potentials, such as the heart.
Five types of epithelia?
Exchange epithelium
Transporting epithelium
Ciliated epithelium
Protective epithelium
Secretory epithelium
What do genotypes become upon transcription?
Phenotypes
What is a phenotype?
The observable characteristics, at the physical, morphologic, or biochemical level, of an individual, as determined by the genotype and environment.
(Advanced Question) How many genes do humans roughly have?
~30,000
(Advanced Question) What chromosome is involved with down syndrome?
21
Order of DNA synthesis?
DNA -> Transcription -> mRNA - > Translation -> protein
What parts of an mRNA are spliced away?
Introns
(Advanced Question) What are added to mRNA after transcription?
a 5’ cap and Poly-A tail
