Ch. 4

Communication channels in plant cells

Plasmodesmata a narrow thread of cytoplasm that passes through the cell walls of adjacent plant cells and allows communication between them.

Cells come into existence through the activity of other cells

True (a cell must make 2 daughter cells with the same DNA, that's how another cell is made)

The cytoplasm is the liquid part of the cell and is outside of the nucleus

True (also referred to as the cytosol)

Prokaryotic cells are bacteria

True (bacteria is single celled; it has no nucleus)

Plant cells do not have a cell wall

False (animal cells are the one's who don't have a cell wall) So animal cells can have various shapes, but plant cells only have the shapes of their cell walls. That's nice for plants, because it gives them the ability to grow up and out, where they can get lots of sunlight for making their food. Cell walls are supporting structures that help the plant to have a fixed shape and protect it from injury. Other than that, it helps to keep the plant turgid so that it can stay firm and upright. Because when it enters a high water potential solution, as water moves in, the water exerts turgor pressure on the cell wall and the cell wall thus exerts an opposing pressure to keep water out. Hence cell wall is needed for the plant. On the other hand, animal cells do not need to keep the structures, as they have the skeletal system to protect the organs and cushion them against any external injuries. animal cells have lysosomes, centrosomes and peroixisomes plant cells have cell wall, central vacuole, and chloroplasts

Plant cells have lysosomes

False (animal cells have lysosomes)

Cellular eating is referred to as "pinocytosis"

False (it is "phagocytosis)

The naked form of the nucleus in the prokaryotes is called the "nucleotide"

False (it is called the "nucleoid") The nucleoid region is the irregularly-shaped section of a prokaryotic cell where DNA is housed. It lacks the membrane that is found around the nucleus of eukaryotic cells. In addition to DNA, the nucleoid may also contain RNA, proteins, and enzymes that can be used for cellular processes.

The naked form of the nucleus in the prokaryotic cell is called the "nucleolus"

False (it is called the "nucleolus" in the eukaryotic cell) It is not present in the Prokaryotic cell

Eukaryotic cells are single celled organisms

False (they have multi nuclei, prokaryotic cells are single celled)

The smooth endoplasmic reticulum (Smooth ER) receives, sorts, and exports the materials within a cell

False (this is the job of the "Rough ER") Rough ER has ribosomes and is abundant in cells s that produce large amounts of protein for export

Communication channels between animal cells

Gap junctions Gap junctions are a specialized intercellular connection between a multitude of animal cell-types. They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulated gate between cells.

The processing, sorting, exporting unit of the cell

The Golgi apparatus The Golgi apparatus gathers simple molecules and combines them to make molecules that are more complex. It then takes those big molecules, packages them in vesicles, and either stores them for later use or sends them out of the cell. It is also the organelle that builds lysosomes (cell digestion machines). Golgi complexes in the plant may also create complex sugars and send them off in secretory vesicles. The vesicles are created in the same way the ER does it. The vesicles are pinched off the membranes and float through the cell.

Produces the male and female hormones

The Smooth ER

Part of the cell that gives the rigidity of the cells are _______

The cell wall Cell wall is a tough, rigid layer that surrounds some types of cells. Cell wall is a characteristic feature to cells of plants, bacteria, fungi, algae and some archaea. It is located outside the cell membrane. The major function of the cell wall is to provide rigidity, tensile strength, structural support, protection against mechanical stress and infection. It also aids in diffusion of gases in and out of the cell.

Cell organelles that are responsible for photosynthesis are _____

The chloroplast Photosynthetic plants synthesize carbon-based energy molecules from the energy in sunlight. Thus, creating an abundance of energy for other organisms. During the process of photosynthesis, cells use carbon dioxide and energy from the Sun to make sugar molecules and oxygen. These sugar molecules are the basis for more complex molecules made by the photosynthetic cell, such as glucose. Then, via respiration processes, cells use oxygen and glucose to synthesize energy-rich carrier molecules, such as ATP, and carbon dioxide is produced as a waste product. Therefore, the synthesis of glucose and its breakdown by cells are opposing processes. Chlorophyll, the primary pigment used in photosynthesis, reflects green light and absorbs red and blue light most strongly. In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll. Chloroplasts are surrounded by a double membrane and contain a third inner membrane, called the thylakoid membrane, that forms long folds within the organelle.

Maintains the cell shape

The cytoskeleton

Cell organelles that are responsible for respiration are _____

The mitochondria Mitochondria are tiny organelles inside cells that are involved in releasing energy from food. This process is known as cellular respiration. It is for this reason that mitochondria are often referred to as the powerhouses of the cell. Cells that need a lot of energy, like muscle cells, can contain thousands of mitochondria.

Part of the cell that is responsible for the entry and exit of molecules that go in and out of the cell ______

The plasma membrane Cell wall is a tough, rigid layer that surrounds some types of cells. Cell wall is a characteristic feature to cells of plants, bacteria, fungi, algae and some archaea. It is located outside the cell membrane. The major function of the cell wall is to provide rigidity, tensile strength, structural support, protection against mechanical stress and infection. It also aids in diffusion of gases in and out of the cell. It separates the contents of the cell from its outside environment and it regulates what enters and exits the cell. Plasma membrane plays a vital role in protecting the integrity of the interior of the cell by allowing only selected substances into the cell and keeping other substances out.

The site of protein synthesis is ______

The ribosomes Ribosomes can be free-floating in the cell or attached to other organelles, such as the rough endoplasmic reticulum. These organelles receive RNA from the cell's nucleus and transcribe and translate the RNA into amino acids. The ribosome then assembles the amino acids into chains. Amino acid chains are also known as proteins. These proteins can then be transported to the rough endoplasmic reticulum and the Golgi apparatus for further synthesis and processing.

The mitochondria is the powerhouse of energy

True

Tight junction cells of animals are called "plasmodesmata"

True

Intermediate filaments provide support

True The function of intermediate filaments is largely mechanical, meaning they provide support for the cell so that other microfilaments can more readily do their transport jobs. Some intermediate filaments are even arranged in a mesh-like pattern to provide for the different support needs of different kinds of cells.

Lysosomes digest macromolecules

True Lysosomes are the cell's recycling centers. They are membrane-bound pouches of enzymes that digest macromolecules such as proteins, carbohydrates, lipids and nucleic acids. However, they also engulf and digest whole organelles, such as mitochondria. Lysosomes digest unwanted molecules and organelles to provide the building blocks for new molecules and organelles.

The central vacuole stores nutrients and regrades waste products

True Vacuoles are storage bubbles found in cells. They are found in both animal and plant cells but are much larger in plant cells. Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination.

Microfilaments are helpful in capturing prey

True (microfilaments aid in cell movement) Microfilaments are present in both plant and animal cells The movement of the cell membrane, organelles, and cytoplasm is all related to the tubules and filaments. You will also find many microfilaments in muscle tissue. They are called myofibrils when you find them in muscles.

The flagella have motor movements

True (the flagella aids in particles moving within the cell; they move in either clockwise or a counterclockwise position; move like a propeller) appears in some plant and animal cells

Organelles are the micro organs of the cell

True (they are mini cells)