Life at a Cellular Level 1-4 Flashcards
Describe the structure of a Prokaryotic cell
Bacteria
Lack nuclear membrane
No mitochondria
No membrane bound structures
Describe the structure of a Eukaryotic cell
Human cells
Nucleus with membrane
Membrane bound structures
Properties of stem cells with regards to differentiation and purpose
Stem cells are multipotent as they can differentiate into many different cell types
What causes the cell to change structure and behavior during cell differentiation ?
The gene expression determines this
How are cancel cells different than normal cell differentiation ?
They over proliferate and fail to specialize.
Displace and replace normal cells if not stopped.
What is apoptosis and what is it closely associated with ?
Programmed cell death and is closely associated with cell proliferation
Define tissues
Functional arrangement of cells
Define organs
Mixture of different tissues
Define a system
Organs with similar functional roles
The membrane lipids are said to be what ?
Amphipathic (Hydrophillic head and hydrophobic tail)
What are the 6 functions of membrane proteins found in the bi-layer?
Transport Intercellular joining Enzyme activity Receptors Attachment to ECM or cytoskeleton
What are the requirements for passive fusion ?
Concentration gradient needed
Lipid soluble molecule
non-polar
What are the requirements for facilitated diffusion ?
Concentration gradient required
Requires carrier molecules
What is a tight junction ?
Cell to cell adhesion which forms a barrier to passive diffusion
What are the main two forms of adhesive junctions ?
Adherens and desmosomes
What is an Adherens junction ?
When two cells are joined through actin filaments
What is a desmosome ?
When two cells are joined through keratin filaments
What is a gap junction ?
Where there is a channel or hole punched between two adjacent cells. Linking the two cell’s cytoplasm together
Name 4 types of cell signalling
1: Synapse - neurotransmitter
2: Direct cell - cell contact - membrane bound protein
3: Paracrine - communicator cell mediator
4: Endocrine - Hormone transport through blood
Describe the properties and structure of the mitochondria
Has an outer layer and intermembranous space, cristae and matrix.
Self-replicating
Their own circular DNA
Synthesize most of their own proteins
Describe the properties and structure of the Nucleus
Contains Nucleoli
Surrounded by nuclear envelope
Contains DNA an RNA
Describe the properties of the Nucleoli
Where RNA is synthesised and ribosomes are assembled. It is inside the nucleus
Describe the properties of the nuclear envelope
It is closely associated with the endoplasmic reticulum. It is formed by a phospholipid bi-layer and contains pores.
What are the two types of DNA ?
Euchromatin
Heterochromatin
Describe the properties and function of the rough E.R. and the golgi apparatus and how are these two organelles linked ?
The rough E.R. is closely associated with the nucleus and arranges the enzymes for direction into the golgi apparatus where they are packaged for sending out of the cell.
What is a lysosome ?
It is what the enzymes are packaged into in the golgi apparatus.
What are the three components of the cytoskeleton and what are they comprised of ?
Microfilaments - actin
Intermediate filaments - fibrous proteins
Microtubules - Tubulin
What do cilia and flagella have in common ?
Both cell surface projections
What are the four elements that make up the human body ?
H, O, N and C
What is the definition of configuration ?
The number of atoms in a molecules
What is the definition of conformation ?
The precise arrangement of atoms in a molecule
What kind of carbon bonds form in configuration ?
Rigid formation Carbon to Carbon double bonds
What kind of carbon bonds form in conformation
Single Carbon to Carbon bonds
What are the two distinct configurations ?
Cis and trans
What are the 5 chemical reactions of life ?
1: Redox reactions
2: Making and breaking carbon bonds
3: Internal rearrangements
4: Group transfers
5: Condensation and hydrolysis reactions
What is an example of an internal rearrangement reaction ?
G-6-P to F-6-P in Glycolysis
What is an example of a group transfer reaction ?
F-6-P to F-1,6- Bisp
Define a protein
Polymers of amino acid monomers, held together with peptide bonds
What does a nucleic acid consist of ?
A phosphate
A base
A pentose sugar
What are the two types of base found in a nucleic acid ?
A pyramidine (U,c and T) A purine (A and G)
What does a polysaccharide consist of ?
Polymer of sugar monomers held together by glycosidic bonds
Name two types of lipid
Saturated and unsaturated
Name two classes of lipid ?
Phospholipid
Tryglyceride
What is the first law of thermodynamics ?
That energy can be converted from one form to another and the universe remains constant.
What is the 2nd law of thermodynamics ?
All energy transformations ultimately lead to more disorder in the universe
What is the equation for Gibbs free energy ?
G = H - TS
What can Gibbs free energy be used to define ?
The spontaneity of a reaction
Spontaneous reactions will occur if…
A system gives up energy.
The entropy increases
What is entropy ?
How disorganized or chaotic a system is
What does the Delta G have to be in order for a spontaneous reaction to occur ?
Negative
Hoe do unfavorable reactions occur ?
They use energy coupling
Define metabolism
Breaking something down to create something new
Define catabolism
Breaking something down to release energy
Define anabolism
Breaking something down to preserve energy
Does spontaneous also equal instantaneous ?
No
What does the hydrolysis of ATP produce and what does this do to unfavorable reactions ?
It releases free energy which drives thermodynamically unfavorable reactions
What does an exergonic, catabolic reaction do to free energy ?
Saves free energy
What does an endergonic, anabolic pathway do to free energy ?
Is supplied with free energy
Name 3 coenzymes, what is their purpose in reactions ?
NAD
NADH
FAD
To store energy from the reaction
What effect does Hydrogen bonds have on molecules ?
H bonds are strongest when the atoms involved are arranged in a straight line.
Molecules containing ‘H’ bonds are soluble in water.
What kind of charge must molecules have to be:
a) Water soluble
b) Insoluble
a) Charged (hydrophillc)
b) Uncharged
Strong acids and strong bases do what in water ?
Completely disassociate
What is a conjugate acid-base pair ?
A proton donor and the corresponding proton acceptor
