Lecture 1 Macromolecules and Cells Flashcards
Macromolecules and Cells
Prokaryotic cells
- A single-celled organism that lacks a nucleus and membrane-bound organelles.
- Prokaryotic cells are the simplest known lifeforms on Earth, including bacteria and archaebacteria
Eukaryotic cells
- A cell that has a nucleus surrounded by a nuclear membrane, and other organelles bound by membranes.
- Eukaryotic cells are the basis of multicellular organisms, such as humans, plants, and animals, and some unicellular organisms, like protozoa
Subcellular Structures
- Nucleus: Stores DNA and controls the cell’s activities
- Mitochondria: Produce chemical energy through respiration
- Ribosomes: Assemble proteins
- Endoplasmic reticulum (ER): A system of tubes and sacs that synthesizes proteins and fatty acids - Rough er – ribosomes –protein synthesis
/Smooth er – no ribosomes - Golgi apparatus: Modifies, sorts, and packages proteins and lipids for use within the cell or secretion outside the cell
- Cytoskeleton: Made of microtubules, actin filaments, and intermediate filaments, this structure helps maintain the cell’s shape and internal organization
- Cell membrane: Controls what substances can enter and exit the cell
Photosynthetic cells
- Contain chlorophyll and other light-sensitive pigments that capture solar energy.
- In the presence of carbon dioxide, such cells are able to convert this solar energy into energy-rich organic molecules, such as glucose
Chemical composition of cell
- Made up of water, inorganic ions, and carbon-based organic molecules.
Macromolecules
- Large polymeric molecules, such as proteins, nucleic acids, and polysaccharides
- Noncovalent bonds specify the shape of a macromolecule and how it binds to other molecules
Nucleic acids
- Large molecules that store and transmit genetic information in cells and viruses. They are made up of smaller units called nucleotides, which are linked together in a chain.
- Made up of phosphoric acid, a five-carbon sugar, and nitrogen-containing bases.
Protein
A large complex molecule made up of one or more chains of amino acids joined by peptide bonds
Polysaccharides
a large carbohydrate molecule made up of many monosaccharides joined by glycosidic bonds
Examples
Cellulose: A structural polysaccharide found in plant cell walls
Chitin: A structural polysaccharide found in arthropod exoskeletons
Starch: A storage polysaccharide found in plants
Glycogen: A storage polysaccharide found in animals
Lipids
Compounds which are relatively insoluble in water, but freely soluble in nonpolar organic solvents
Group of organic compounds that are fatty, waxy, or oily
Subcellular organisation
The structure and function of the parts within a cell. Subcellular structures are called organelles, and they perform specific tasks to keep the cell functioning.
Eubacterial shapes
Cocci - spherical
bacilli - rod shaped
spirilli - helical
What makes Archaea unique
- Have certain features that are unique or are shared with eukaryotes – placed in separate kigdom
- Archaea are found in extreme conditions
- Derive energy from e.g. oxidation of organic compounds with sulfur (S2) rather than O2
What are peroxisomes
- Fatty acid degradation and conversion of hydrogen peroxide to water and oxygen
What are lysosomes
- Digest macromolecules using enzymes transported from Golgi via transport vesicles
