5 Written questions
5 Matching questions
- Mobile carriers
- Tight junctions
- a Two such carriers are found in the ETC in the form of ubiquinone (or Q) and the protein cytochrome c.
Small lipid-bounded spheres which transport proteins, glyco proteins and newly synthesized lipids (which are imbedded in the sphere itself) from the endoplasmic reticulum to the Golgi Apparatus or from the Golgi apparatus to another destination. They move short distances by the process of difussion, moving long distances requires the assistance of proteins associated with microtubules.
- c Cellular compartments in cell biology comprise all closed parts within a cell, usually surrounded by a single or double lipid layer membrane. Most organelles are compartments like mitochondria, chloroplasts (in photosynthetic organisms), peroxisomes, lysosomes, the endoplasmic reticulum, the cell nucleus or the Golgi apparatus. Smaller elements like vesicles, and sometimes even microtubules can also be counted as compartments.
These cell junctions are linked very closely and prevent movement of membrane proteins, in the skin for example or in the role mainting the polarity of the cells of the intestine.
Intermediate filament proteins which protect the structure of the nucleas, they polymerize to from a network of filaments that lie just within the nuclear membrane. The network of these filament proteins is called the nuclear lamina.
5 Multiple choice questions
- This process is the directed degradation (digestion) of proteins which fail to fold correctly by cellular enzymes called proteases or by intramolecular digestion.
In glycolysis, phosphoenolpyruvate (PEP) is converted to pyruvate by pyruvate kinase. This reaction is strongly exergonic and irreversible; in gluconeogenesis, it takes two enzymes, pyruvate carboxylase and PEP carboxykinase, to catalyze the reverse transformation of pyruvate to PEP. The pyruvate is removed from the mitochondria via a membrane bound protein carrier known as the pyruvate transporter.
Special proteins around which DNA is wrapped.
Phospholipids are a class of lipids and are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from sphingosine instead of glycerol. The first phospholipid identified as such in biological tissues was lecithin, or phosphatidylcholine, in the egg yolk, by Theodore Nicolas Gobley, a French chemist and pharmacist, in 1847. The structure of the a phospholipid molecule consists of hydrophobic tails and hydrophilic heads, it also consists of cholesterol molecules which are found in-between the spaces of the phospholipid.
- These lipids are molecules that are mostly lipid-like (hydrophobic) in structure, but at one end have a region that is polar or ionic (hydrophilic). The hydrophilic region is usually referred to as the head group, and the lipid portion is known as the tail(s). Cell membranes typically consist of three separate classes of lipids of this type. These include phospholipids, glycolipids, and steroids.
5 True/False questions
Vmax → Shorthand for molecular mass.
Primary active transport →
The name often given to tissue that contain a large proportion of extracellular matrix. In this tissues the cells that are secreting the materials are often quite far from each other.
The point on a rectangular hyperbola which is half the value of the Vmax. It indicates the affinity of an enzyme and substrate a high value means low affinity and a low value means high affinity (the enzyme substrate locks more securely and takes longer to seperate and release products).
N-CAMS/Neural Cell Adehesion Molecules → Membrane glycoproteins with an extracellular region made up of several domains. They are involved in the formation of intercellular junctions in neural tissue and unlike cadherins are not calcium dependant. As with cadherins they have sialic acid sugar components giving the cell membrane a negative charge discouragin inter cell adhesion.
Respiratory control → The name given to 'bunched together' electron carriers of the electron transport chain.