102 Cell Biology Flashcards
What is it called when organisms only have one cell?
Unicellular
What is “cytology” ?
The study of cells
What are eukaryotic cells?
Organisms whose cells have a membrane-bound nucleus
What is the diameter for eukaryotic cells?
10-20μm
What are the ESSENTIAL Oral Cell Types?
1) Osteoblasts
2) Osteoclasts
3) Fibroblasts
4) Ameleoblasts
5) Odontoblasts
Which oral cell type is involved with the building of bone?
Osteoblasts
Which oral cell type is involved in enamel formation?
Ameleoblasts
What do osteoclasts do?
“Crumbles” breaks down bone
Which oral cell type is responsible for forming dentine?
Odontoblasts
What are some structural features of nerve cells?
1) Surface that is sensitive to stimuli
2) Long Extensions
What are some structural features of muscle cells?
1) Elongated, threadlike
2) Contain tiny fibres that slide together forcefully
What are some functions of nerve cells?
1) Can detect changes in internal or external environment.
2) Transmit nerve impulses from one part of the body to another.
What are the four macromolecules?
- Carbohydrates
- Proteins
- Lipids
- Nucleic Acids
What elements are carbohydrates composed of?
Carbon (C), Hydrogen (H) and Oxygen (O)
What are sugars and some examples of them?
Sugars are simple carbohydrates.
Includes glucose, fructose, galactose and mannose.
Sugars may be polymerised into larger molecules called…?
Polysaccharides. E.g. glycogen, starch, cellulose.
What are proteins and what are they composed of?
Proteins are polymers of AMINO ACIDS.
They are composed of Carbon, Hydrogen, Oxygen, Nitrogen and Sulphur, (Selenium).
How many common amino acids are there?
20 amino acids!
How many ESSENTIAL amino acids are there?
9 (must obtain from food!)
What are short polymers of amino acids called?
Peptides
What are long polymers of amino acids called?
Proteins
Amino acid side chains may be…?
- Charged
- Uncharged
-Polar/Hydrophilic
-Non-Polar/Hydrophobic
What is Glycogen?
Glycogen is a large branded polymer of glucose.
It is the main energy storage molecule of animals.
What are enzymes?
Enzymes are the macromolecules that actually DO things - all enzymes are proteins.
Why are enzymes called “chemical catalysts”?
Because they promote or accelerate specific chemical reactions.
How is energy provided to enzymes?
Through the substrate or ATP.
What does the suffix “-ase” refer to?
What are some examples of this?
-ase usually used for enzymes.
E.g. proteinase = enzyme that breaks down protein. Lipase = enzyme that breaks down lipids/fats. Amylase = enzyme that breaks down starch.
What does the suffix “-ose” refer to?
What are some examples of this?
-ose refers to sugar.
E.g. hexose = 6-carbon (hexacarbon) sugar like glucose, fructose (-ose from fruit)
What does the suffix “-some” refer to?
What are some examples of this?
-some refers to a cellular entity with a function.
E.g. lysosome = cellular organelle that destroys foreign particles.
What is the chemical functional group for -OH?
Hydroxyl group (H = hydrogen, O = oxygen)
What is the chemical function group for -COOH?
Carboxyl group (acids and lipids/fats)
What is the chemical functional group for -SH?
Sulphydryl (thiol) group - sulphur instead of oxygen.
What is the chemical function group for -PO4?
Phosphate group (P = phosphorus + 3-4 oxygens)
What is the chemical functional group for -NH2?
Amino group
(N = nitrogen)
What is Adenosine Triphosphate (ATP)?
ATP is the common energy currency of cells.
Where is energy stored?
Energy is stored in the high-energy bonds linking the phosphate molecules.
As the terminal phosphate bond is broken, energy is provided to the enzyme.
What are lipids composed of?
Lipids are composed of Carbon (C), Hydrogen (H) and Oxygen (O).
What are the two components in a phospholipid?
A phosphate head group - Hydrophilic
And a lipid tail - Hydrophobic
What are the two principal molecules in nucleic acids?
Ribonucleic Acid (RNA) and
Deoxyribonucleic Acid (DNA)
What is the largest biomolecule?
DNA!
What are nucleotides composed of?
Nucleotides are composed of a S-carbon sugar (deoxyribose or ribose) attached to a nitrogenous base.
What are the four constituent bases of nucleic acids?
Adenine (A), Guanine (G), Pyrimidine-cytosine (C), Thymine (T).
How many genes does the human genome have?
20, 500 genes
The flow of sequential information from gene to protein and never backward
The Central Dogma
DNA ➡️ RNA ➡️ Protein
What is it called when not every gene is switched on at the same time?
“Mosaics”
What are lysosomes and where are they found?
Lysosomes are part of the cells immune system. Only found in cells that are involved in destroying stuff.
What is endocytosis?
A process by which foreign objects are taken out.
What is another name for the Cytoplasmic Membrane?
Cell or Plasma Membrane
How thick is the Cytoplasmic Membrane?
Approx. 7.5nm thick
What does the cytoplasmic membrane do?
Separates cytoplasm from surrounding environment and maintains integrity of cell. Also controls energy and exit of molecules in and out of the cell.
What is the role of the membrane proteins?
Membrane proteins control movement of molecules across membrane (specificity). They interact with extra cellular molecules such as hormones (receptors). Bind the cell to neighbouring cell.
What is cytoplasm?
Cytoplasm is a water-based, gel-like substance containing many different proteins and other molecules suspended in cytosol.
Organelles can be both…?
Membranous or Non-Membranous
What are the two types Endoplasmic Reticulum (ER)?
- Smooth ER: lipid synthesis
- Rough (ribosomes) ER: protein synthesis
What are the cells protein factories?
Ribosomes
What are ribosomes composed of?
RNA and Protein
What is the subunit for bacterial ribosomes?
70S (50S + 30S)
What is the Golgi Apparatus?
Membranous organelle composed of stacked cisternae (sacs)
Where is the Golgi Apparatus located?
Usually near the nucleus.
What is the function of the Golgi Apparatus?
Functions to further “process” and “package” proteins for secretion (export).
A membranous organelle also known as the “power station of the cell”.
Mitochondria
How many membranes are present in the mitochondria?
TWO! Inner membrane and outer membrane.
What are proteasomes and where are they found?
Proteasomes are hollow proteinaceous “drums” (non-membranous) found in nucleus and cytoplasm.
What is the role of proteasomes?
Proteasomes destroy unwanted proteins.
