Introduction To Cell And Tissue Biomedicine Flashcards
In order of smallest to biggest, what are the components of the human body?
Atom Molecule Organelle Cell Tissue Organ Organ system Organism Body
What can a electronic microscope see?
Small molecules Lipids Proteins Virus Bacteria Organelles Eukaryotic cells
What can a light microscope see?
Bacteria
Organelle
Eukaryotic cells
What are elements?
Primary chemical constituents of all matter; fundamental substances that cannot be chemically interconverted
What is an atom?
Smallest unit of a chemical element; cannot be broken down but do contain sub-atomic particles where protons + neutrons make up the nucleus but also electrons
What are neutrons?
Uncharged sub-atomic particles; number varies but roughly the same as the proton no. in an atom
What are protons?
+vely charged sub-atomic particles; each element has a different no. of protons
What is the relative mass of an atom equal to?
The number of particles in the nucleus of an atom
What are electrons?
-vely charged sub-atomic particles than orbit the nucleus; no. = no. of protons but electrons can be gained or lost
What are ions?
Charged entities formed when atoms lose or gain electrons (element has not changed because no. of protons is constant)
What is a molecule?
When atoms ‘share’ electrons in a covalent bond with another element - different elements can be combined to make highly complex compounds
What does a elements position in the periodic table indicate?
Its predisposition to lose/gain/share a specific no. of electrons
What does the column number indicate about an element?
That these atoms generally share this no. of electrons forming this no. of covalent bonds in a molecule
What are elements on the left or right of the periodic table predisposed to do?
Left: generally lose electrons to form +ve ions
Right: generally gains an electron to form a -ve ion
What are the main elements that make up the body? In what percentage?
N: 3% H: 10% C: 18% O2: 65% Other: 4%
What are cells?
Basic fundamental unit of life
What are tissues?
Group of cells with a similar function
What are organs?
Collection of tissues with related functions set within a certain space
Describe the structure of a cell.
Each cell is enveloped by a plasma membrane + divided internally:
- Nucleus: store of DNA
- Cytoplasm: aqueous gel-like substance within cellular contents are dissolved
- Other organelles: structures within cell with specialist functions
Why does the nucleus and other organelles of cells mostly have their own membranes?
Enables compartmentalisation of biochemical processes + optimisation of conditions for each of the reactions in each compartment
What are the 5 types of human tissue?
Epithelia Muscle Connective tissue Blood Nervous tissue
What is blood composed of?
Cells: RBCs, platelets + WBCs
Plasma: fluid + proteins
What is the structure of RBCs? Relate this to its function.
Highly malleable + have maximum SA (biconcave disc with 2 concave surfaces) as they are specialised to carry O2 to tissues + remove CO2
What are platelets? What is their function?
Small fragments of cells (megakaryocytes) that function to form a plug to maintain vascular integrity
What do WBCs do?
Involved in immunity + defence against infection
What is the nervous system composed of?
‘Doing’ cells = neurones
‘Supporting’ cells = neuroglia e.g. astrocytes, oligodendrocytes, microglia + ependymal cells
What is the defining feature of a muscle?
Its ability to contract; although contractility is present in all cells it is the key feature of muscle cells as it is more pronounced
Why does contractility happen?
Due to fibrillary proteins in cytoplasm
How can muscle cells be arranged?
As single cells = myoepithelial cells
In groups = muscles
Where are myoepithelial cells found?
Contractile parts of epithelia or glands
In groups making muscles
What are the 3 types of muscle?
- Skeletal
- Cardiac
- Visceral/SM
What prefix is applied to organelles etc. within a muscle?
Sarco
What is connective tissue?
Tissue that provides structural + metabolic support for other specialised cells + tissues
What are the 2 types of connective tissue?
- Loose: packing material e.g. lamina propria of gut
2. Dense: rigid support e.g. dermis or tendons
What are the 2 components of connective tissue?
- Cells: fibroblasts, adipocytes + cells of IS (e.g. macrophages)
- ECM: ground substance + protein fibres
What do the cells in connective tissue do?
Important to structural role of connective tissue; responsible for synthesis + maintenance of the matrix + for storing fat
What is epithelia? How can it specialise?
Lines many surfaces of the body
Can be specialised to provide physical protection, diffusion, absorption/secretion or containment
How can cellular life be classified?
Prokaryotes: no nucleus e.g. bacteria + archaea
Eukaryotes: nucleus e.g. protists, fungi, plants + animal cells
What is an autotroph?
Cell that can provide all their required complex organic molecules (e.g. carbohydrates) from simple substances in the environment using energy from light (photosynthesis) or chemical sources (chemosynthesis)
What are heterotrophs?
Cells that cannot produce all their required complex organic molecules (e.g. carbohydrates) so they need to consume them in their diet
What are the features of bacteria?
Peptidoglycan cell wall
Unicellular
Autotrophic/heterotrophic
What are the 2 types of bacteria?
Gram -ve: thin cell wall so lose violent stain + have to be further stained pink - also contain LPS
Gram +ve: purple because of their thick peptidoglycan cell wall which retains crystal violet dye
What are the features of archaea?
Cell wall with no peptidoglycan
Unicellular
Autotrophic/heterotrophic
What are the features of protists?
Mixed cell wall
Unicellular/multicellular
Autotrophic/heterotrophic
What are the features of fungi?
Cell wall present
Unicellular/multicellular
Heterotrophic
What are the features of plants?
Cell wall present with cellulose
Multicellular
Autotrophic
What are the features of animals?
No cell wall
Multicellular
Heterotrophic
