Answer: B) proteins in the membrane act like gates to control entrance and exit of molecules.
Explanation: Plasma membrane is composed of phospholipids bilayer in which the hydrophobic regions of the phospholipids face each other to form the core of the bilayer. Proteins are embedded in the bilayer through an interaction between the amino acid side chains and the nonpolar acyl chains of the phospholipids. The embedded membrane proteins form channels for passage of ions and other molecules. Each membrane protein is selected for one or more ions or molecules that passes through it. The membrane is said to be semipermeable because it allows the passage of some molecules and excludes the passage of others.
Answer:
C. Tape Measure
Explanation:
Thats the best of the options.
Asthma. When most people that have this disease encounter one of those things then they need special little tool which is called an inhaler.
Answer:
They produce oxygen and act as primary producer
Explanation:
Marine algae are important to marine and terrestrial population because they are responsible for fixing carbon dioxide to produce oxygen as well as act as the primary producer in the marine ecosystem.
<em>A large percentage of the oxygen available for aerobic respiration in several terrestrial organisms are produced by marine algae through the process of photosynthesis.</em>
<em>Also, marine algae act as the primary producer in the food chain and food web of the marine ecosystem. Without them, the food chain would be broken and biological activities would be disrupted in the marine ecosystem.</em>
Answer:Proteins are synthesised (made) by the ribosomes using messenger RNA transcribed from DNA in the nucleus.
Explanation:
In every eukaryotic cell, such as plants and animals, there is DNA in the nucleus. The nucleus is an area surrounded by a membrane (nuclear membrane) which has some pores for materials to enter and exit, but these are controlled. The DNA is the cell's instructions, it is a series of code that can be transcribed and translated to make proteins. As in the image below DNA is a series of bases attached to a sugar phosphate backbone and bonded to another base pair to made a ladder, this ladder is twisted making the shaped called a double helix . There are four base pairs: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). The bases have bases they bond to making complementary base pairs , A and T bond together while the C and G bond together. on each strand of DNA one end is labelled 5' (read as 5 prime) and other end is the 3'. The 5' end base pairs of one strand are always attached to the 3' end of the complementary strand. Labelling the ends helps us to describe in which direction DNA is read.
