Cell The Unit of Life Test - 12

In eukaryotic cell, ribosome’s are of 80S type. However, 70S ribosome’s, occur in plastids and mitochondria.

Plants are autotrophs and synthesise their food in the process of photosynthesis with the help of chloroplast (plastid).

Temperature, molecule size, molecule charge, and concentration gradients all affect the rate at which diffusion takes place.

The cells are held together by a Ca-pectate layer called middle lamella.

Cristae are found in wall of mitochondria.

The charged or polar lining of the channel proteins allows passage of polar and charged molecules.

Plasmodesmata connections help in movement of substances between cells.

Cell theory was proposed in 1838 by Matthias Schleiden and by Theodor Schwann. The cell theory says that: All organisms are composed of one or more cells. All cells come from pre-existing cells. All vital functions of an organism occur within cells. Cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

Lysosome contain different hydrolytic enzymes, such as proteases, lipases, and nucleases that are capable of breaking down all types of biological polymers (e.g. proteins, nucleic acids, carbohydrates, and lipids) that enter the cell or are no longer useful to the cell.

Several isozymes of malate dehydrogenase exist. There are two main isoforms in eukaryotic cells. One is found in the mitochondrial matrix, participating as a key enzyme in the citric acid cycle that catalyzes the oxidation of malate

Aerobic respiration occurs in the MITOCHONDRIAL MATRIX or on the inside of the inner membrane of mitochondria (the "powerhouse" of the cell). In contrast, anaerobic respiration (without \(O_2\)) strictly occurs in the cytoplasm of the cell (a process called GLYCOLYSIS).

In some protists and yeast cells (not sure about other cell types), the number of mitochondria increases when the cells are deprived of glucose (but not oxygen)

Yes, endergonic reactions are coupled to the hydrolysis of ATP, which is exergonic. -Yes, the synthesis of ATP is Endergonic.

ATP can only be made if it is coupled to an exergonic pathway reaction. The synthesis/hydrolysis of ATP and the oxidation/reduction of NADH/NAD+ are the coupled or side reactions.

Racker particle or Fraction \((F_1)\) particle is found in Mitochondria and is a part of larger ATP synthase complex. These are found on the cristae of mitochondria

Oxysomes are the ones called as \(F_1\) or elementary particles. \(F_1\) particles are present in the inner mitochondrial space of the mitochondrion.

Chromoplasts are plastids that, due to their high carotenoid content, are colored red, orange, or yellow.

Explanations:

Nucleus is the brain of the cell and controls most of its functions. Without a nucleus, the cell will not know what to do and there would be no cell division.

Protein synthesis would either cease or incorrect proteins would be formed. All this would result in cell death.

Anything less than a complete structure of a cell does not ensure independent living. Hence, cell is the fundamental structural and functional unit of all living organisms.

Mitochondria are double membrane cell organelles with the outer membrane and inner membrane. Lysosome is a single membrane bound vesicular structure. It contains many hydrolytic enzymes and commonly called as suicidal bag of the cells.

Ribosome is a granular structure, without membrane. It consists of RNA and proteins and is the protein builders or the protein synthesisers of the cell.