Cells and Life - GED Science

Glycolysis is the first step of glucose breakdown in cells. This process takes place in the cytosol.

The second step of cellular respiration, the citric acid cycle, takes place in the mitochondrial matrix. The third step, the electron transport chain, takes place on the inner mitochondrial membrane and requires protons to be concentrated within the intermembrane space.

Glycolysis is the first step in cell metabolism. It is responsible for converting glucose (a 6-carbon sugar) into two molecules of pyruvate (a 3-carbon sugar). Glycolysis occurs in the cytoplasm, where the sugar molecules interact directly with enzymes. After pyruvate is created, it is transported to the mitochondria for the remainder of cellular respiration (the citric acid cycle and electron transport chain).

Though plants undergo photosynthesis, they also use cellular respiration. Glycolysis takes place in both animal and plant cells.

Photosynthesis is the process by which plants use the sun's energy to convert water and carbon dioxide into glucose and oxygen .

The equation is the equation for cellular respiration. Cellular respiration happens inside the mitochondria and chloroplast for those cells containing chloroplasts.

The plasma membrane of the cell acts as a semi-permeable barrier, regulating what can enter and exit the cell. Only small, nonpolar molecules are able to cross the membrane via diffusion, without the assistance of protein channels. Larger molecules will be blocked, as will molecules that are charged or polar.

This principle is true for both prokaryotic and eukaryotic cells, and is not affected by the presence of a cell wall. Virtually all organic molecules contain carbon and hydrogen; the presence of these atoms will not affect the molecule's ability to cross the membrane.

A hypertonic solution will have a higher solute concentration than the cell. To reach equilibrium, water must flow so that the concentration fo the solution is equal to the concentration of the cell. In order for this to happen, water must enter the solution, diluting it and reducing the concentration. Water will flow out of the cell and into the solution.

Note that the membrane of the cell will prevent ions from crossing.

The "water-loving" hydrophilic heads of phospholipids orient themselves outwards towards the watery cytoplasm inside the cell and interstitial fluid outside the cell. Meanwhile, the "water-fearing" hydrophobic tails of phospholipids orient themselves inwards toward one another.

Interstitial fluid is the substance surrounding living tissue cells, its solute concentration is critical to the maintenance of homeostasis for the cells. Cells may have to spend valuable energy to keep unwanted materials from passing through their semi-permeable membranes in some conditions.

Diffusion, facilitated diffusion, and osmosis are all examples of passive transport because no energy is required to move molecules across the cell membrane. The driving force is the concentration gradient of the substance.

Water can pass through the cell membrane without using energy. We call this passive transport. Diffusion is a type of passive transport and osmosis is specifically the diffusion of water molecules. So all of the answers are correct.

Active transport always requires energy since molecules are being pumped against their concentration gradients by being transported from areas of low concentration to areas of high concentration. Osmosis and diffusion are examples of passive transport and do not require energy.

In a hypertonic solution, the cell has a greater concentration of water molecules inside it than the solution does. Because of this, the water will move out of the cell in an effort to balance the concentration of water molecules both inside and outside of the cell.

Metaphase is characterized by chromosomes moving to the narrow central zone of the cell called the metaphase plate/equator.

Mitosis creates two diploid daughter cells that are identical to the original cell. This process creates somatic (body cells).

One of the primary differences between plant cells and animal cells is that plant cells must be able to undergo photosynthesis. Photosynthesis takes place in the chloroplasts, which contain the pigment chlorophyll. Chloroplasts are not found in animal cells, but are found in plant cells.

Both animal and plant cells contain Golgi bodies, smooth endoplasmic reticulum, and mitochondria.

The mitochondria are organelles that are often referred to as the "power plant" of the cell. Mitochondria are responsible for extracting energy from food molecules and binding it in the high energy bonds of the ATP molecule.

Ribosomes are composed of a unique type of RNA, rRNA, and are located within the cytoplasm of the cell and on the surface of the rough endoplasmic reticulum. Here, proteins are assembled from amino acids piece by piece using instructions copied from DNA.

The Golgi apparatus can be thought of as the "shipping center" of the cell. Here, proteins and other materials are packaged in vesicles which are transported to other sites in the cell or outside the cell membrane for "export".

The chloroplast is unique to plant cells (and some bacteria and protists), and is the site of photosynthesis. Almost all energy used by life is captured by this organelle. All other answers listed can be found in both plant and animal cells.