Answer:
Proteins and lipids exist as separate but loosely attached molecules that can move around
Explanation:
Cell membranes are mainly composed of lipids, proteins, and also carbohydrates. Phospholipids are the most abundant type of lipid and the main constituent of the cell membranes. Membrane proteins are divided into two types according to their interactions with the cell membrane: 1-integral (intrinsic) and peripheral (extrinsic) proteins. These peripheral proteins are loosely attached by ionic bonds or calcium bridges with the phosphate heads of the phospholipids; whereas integral membrane proteins contain side chains that interact with fatty acyl groups of the phospholipids. Cell membrane fluidity indicates how easily lipids (e.g., phospholipids and cholesterol) and proteins (e.g., intrinsic proteins) diffuse laterally in the cell membrane. This fluidity is affected by the amount of cholesterol, temperature, and the ratio of unsaturated to saturated fatty acids. Saturated fatty acids have no double bonds in the hydrocarbon chain, whereas unsaturated fatty acids have at least one double bond (these double bonds increase fluidity). Moreover, higher temperatures increase membrane fluidity, whereas cholesterol molecules function to regulate membrane fluidity: at high temperatures cholesterol molecules stabilize the membrane, whereas at low temperatures intercalate between phospholipids, thereby preventing them from clustering together.
Answer:
c. decaying plant and animal remains
Step 1
Glucose enters glycolysis pathway and glycolysis yields pyruvate, then pyruvate undergoes processing.
step 2
Pyruvate processing ;releases acetylCOA which joins the citric acid cycle.
Step 3
The citric acid cycle yields 2ATP and CO2 and also releases NADH and FADH2 to electron transport chain and chemiosmosis.
Step 4
Chemiosmosis and electron transport chain yields 25 ATP molecules and H2O Oxygen enters electron transport chain and osmosis.
The phylum Arthropoda contains a wide diversity of animals with hard exoskeletons and jointed appendages. Many familiar species belong to the phylum Arthropoda—insects, spiders, scorpions, centipedes, and millipedes on land; crabs, crayfish, shrimp, lobsters, and barnacles in water (Fig. 3.72).
I think that the correct answer to this question is D .
