De: Cell And Membrane

Plant cells have one big vacuole used for storage, while animal cells have lots of small vacuoles. The vacuole in plant cells is a large membrane-bound organelle that stores water, nutrients, and waste products. It also helps maintain the turgidity and shape of the plant cell. In contrast, animal cells have multiple small vacuoles that perform various functions, such as storing waste, regulating pH, and maintaining osmotic balance. The presence of one large vacuole in plant cells and multiple small vacuoles in animal cells is a key difference between the two cell types.

Photosynthesis is a process carried out by plants and some other organisms to convert sunlight, water, and carbon dioxide into glucose and oxygen. Chloroplasts are the organelles responsible for photosynthesis in plant cells. They contain a green pigment called chlorophyll, which captures sunlight and uses it to fuel the chemical reactions of photosynthesis. Therefore, the correct answer is chloroplasts.

Maple trees are plants and have chloroplasts, which are responsible for photosynthesis, converting sunlight into energy. Human cells do not have chloroplasts as they do not perform photosynthesis. Additionally, plant cells have cell walls, which provide support and protection to the cell. Human cells do not have cell walls; instead, they have cell membranes that regulate the movement of substances in and out of the cell. Therefore, chloroplasts and cell walls would be found in a maple tree cell but not a human cell.

Mitochondria create ATP energy for a cell. ATP is the main energy source for cellular activities, and mitochondria are responsible for producing it through a process called cellular respiration. They have an inner membrane that contains proteins involved in ATP synthesis. This organelle is often referred to as the "powerhouse" of the cell due to its crucial role in energy production. Chloroplasts, on the other hand, are responsible for photosynthesis in plant cells, while ribosomes are involved in protein synthesis, and the nucleus contains genetic material.

Passive transport is the correct answer because it refers to the process by which substances move across the cell membrane without the need for energy expenditure. Unlike active transport, which requires energy, passive transport relies on the concentration gradient to allow molecules to move from an area of higher concentration to an area of lower concentration. This can occur through diffusion, osmosis, or facilitated diffusion. Endocytosis and phagocytosis, on the other hand, involve the engulfing of substances by the cell membrane and require energy, making them active transport processes.

The correct answer is vacuole. Vacuoles are plant organelles that store water, as well as other substances such as nutrients and waste products. They play a crucial role in maintaining the turgidity and shape of plant cells, as well as regulating the concentration of solutes within the cell. Vacuoles are membrane-bound structures that can occupy a significant portion of the cell's volume, and their size and function can vary depending on the specific needs of the plant.

The cell membrane is described as semi-permeable because it selectively allows certain substances to pass through while preventing others from entering or leaving the cell. This characteristic is crucial for maintaining the cell's internal environment and regulating the movement of molecules such as nutrients and waste products. The term "semi-permeable" accurately captures this property of the cell membrane without any additional explanation needed.

The cell membrane is responsible for determining which substances can enter and exit the cell. It acts as a selective barrier, allowing certain molecules to pass through while blocking others. This process is crucial for maintaining homeostasis and regulating the cell's internal environment. The other organelles listed, such as ribosomes, endoplasmic reticulum, and lysosomes, have different functions and are not directly involved in controlling the movement of substances in and out of the cell.

Bacteria are known as prokaryotes because they lack a nucleus. Prokaryotes are characterized by the absence of a membrane-bound nucleus and other membrane-bound organelles. Instead, their genetic material is present in a region called the nucleoid. Bacteria are single-celled organisms that have a simple cellular structure compared to eukaryotes, which have a true nucleus and other complex organelles. Phagocytes are a type of immune cell that engulf and destroy pathogens, while endocytes and eukaryotes are not accurate terms to describe bacteria.

The cell membrane is responsible for determining which substances can enter and exit the cell. It acts as a selectively permeable barrier, allowing certain molecules to pass through while blocking others. This process is essential for maintaining homeostasis and regulating the cell's internal environment. The cell membrane contains various proteins and channels that facilitate the movement of substances in and out of the cell, controlling the exchange of nutrients, waste products, and signaling molecules. Therefore, the cell membrane is the correct answer to the question.

Active transport is the movement of molecules from an area of lower concentration to an area of higher concentration. Because this defies the law of diffusion, it takes the proteins on the membrane energy to transport molecules across.

Diffusion is the correct answer because it refers to the process in which substances move from regions of high concentration to regions of low concentration. This movement occurs due to the random motion of particles, causing them to spread out and distribute evenly. Diffusion does not require energy input and is a passive process. Phagocytosis, active transport, and endocytosis all involve the movement of substances, but they do not specifically refer to the movement from high to low concentration.

Animal cells have mitochondria because they are the powerhouses of the cell, responsible for producing energy in the form of ATP through cellular respiration. Chloroplasts are found in plant cells and are responsible for photosynthesis. Cell walls are also found in plant cells and provide structural support. One large vacuole is found in plant cells and serves various functions including storage and maintaining cell turgidity. Therefore, the correct answer is mitochondria.

Proteins are made in ribosomes. Ribosomes are small, complex structures found in cells where protein synthesis occurs. They are responsible for reading the genetic instructions in the form of RNA and assembling amino acids into proteins. While chloroplasts, mitochondria, and the nucleus play important roles in cellular processes, protein synthesis specifically takes place in ribosomes.

Both plant and animal cells have mitochondria. Mitochondria are organelles that are responsible for producing energy in the form of ATP through cellular respiration. They are found in both plant and animal cells and play a crucial role in providing energy for various cellular processes. Chloroplasts, on the other hand, are only found in plant cells and are responsible for photosynthesis, the process by which plants convert sunlight into energy. Therefore, the correct answer is mitochondria.

The nucleolus is the correct answer because it is the site where ribosomes are assembled. Ribosomes are essential cellular structures involved in protein synthesis, and their assembly occurs within the nucleolus. The nucleolus is a distinct region within the nucleus of a cell and contains the necessary components for ribosome production. Therefore, the nucleolus plays a crucial role in the synthesis and assembly of ribosomes, making it the correct answer in this context.

The cell theory states that all organisms are composed of cells, that all cells come from preexisting cells, and that it is accepted today by biologists as applying to virtually all forms of life. However, the statement that bacteria and other small organisms can arise spontaneously is not true according to the cell theory. The theory suggests that all cells come from preexisting cells, meaning that new cells are formed through cell division rather than spontaneously appearing.

The nucleolus is the correct answer because it is the site where ribosomes are assembled. Ribosomes are essential cellular structures involved in protein synthesis. The nucleolus is a substructure within the nucleus of a cell and is responsible for producing and assembling the components of ribosomes. Therefore, the nucleolus plays a crucial role in the formation of ribosomes, making it the correct answer in this context.

The equation -iCRT is used to calculate the solute potential. In this equation, i represents the ionization constant, C represents the molar concentration of the solute, R represents the ideal gas constant, and T represents the temperature in Kelvin. In this question, the sucrose concentration is given as 0.7 M and the temperature is 3 degrees Celsius. To convert the temperature to Kelvin, we add 273 to it, giving us 276 K. Since sucrose does not ionize, the ionization constant (i) is 1. Plugging these values into the equation, we get -1 * 1 * 0.7 * 0.0831 * 276 = -16.1. Therefore, the solute potential is -16.1.

Lysosomes are cell structures involved in the digestion and breakdown of cellular waste and debris, including worn-out organelles such as ribosomes. They contain enzymes that can break down various molecules, including proteins. Therefore, lysosomes would be responsible for digesting worn-out ribosomes in the cell.

The correct answer is nucleus and mitochondria. DNA is found in the nucleus of a cell, where it is stored and replicated. The mitochondria also contain DNA, although it is much smaller and separate from the nuclear DNA. The DNA in mitochondria is responsible for producing proteins essential for the mitochondria's function in energy production.

The endoplasmic reticulum acts as the "travel system" for the cell, allowing substances to move throughout the cell from one organelle to another. It is a network of membranes that extends from the nucleus to the cell membrane, and it is involved in the synthesis, modification, and transport of proteins and lipids. The rough endoplasmic reticulum, which is studded with ribosomes, is responsible for protein synthesis, while the smooth endoplasmic reticulum is involved in lipid metabolism and detoxification of drugs and toxins. Therefore, the endoplasmic reticulum plays a crucial role in maintaining the internal organization and function of the cell.

The SER (Smooth Endoplasmic Reticulum) is responsible for various functions in the cell. It plays a role in detoxification, lipid metabolism, and stores calcium ions. However, ATP production is not a function of the SER. ATP (Adenosine Triphosphate) is primarily produced in the mitochondria through cellular respiration. The SER is involved in the synthesis of lipids and steroids, but not in the production of ATP.

Eukaryotic cells contain ribosomes that are larger than those of prokaryotic cells. Unlike prokaryotic cells, eukaryotic cells have a true nucleus containing chromosomes. Eukaryotic cells also have membrane-bounded compartments, many organelles in the cytoplasm, and mitochondria. The statement that they contain ribosomes that are smaller than those of prokaryotic cells is not true.

Lysosomes are organelles found in cells that contain digestive enzymes. These enzymes are responsible for breaking down various molecules, such as proteins, lipids, and carbohydrates, through hydrolysis. This process allows the cell to obtain nutrients from the broken-down molecules and recycle waste materials. Therefore, lysosomes catalyze hydrolysis, making them the correct answer.

When a red blood cell is placed in a hypertonic medium, the concentration of solutes outside the cell is higher than inside the cell. As a result, water from inside the cell moves out to the surrounding medium through osmosis, causing the cell to lose water and shrink. This is because water moves from an area of lower solute concentration (inside the cell) to an area of higher solute concentration (outside the cell) in order to equalize the concentration on both sides. Therefore, the correct answer is shrink.

Cell surface proteins play a crucial role in various cellular functions, including receptor binding, cell signaling, and transport of molecules across the cell membrane. However, digestion of starch is primarily carried out by enzymes such as amylase, which are not located on the cell surface. Therefore, digestion of starch is not a function of cell surface proteins.

Water moves across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration. This process is known as osmosis. Therefore, the solution on the side of the membrane with the least solute will have a higher concentration of water, making it more concentrated in water.

The nucleolus is responsible for making ribosomes. Ribosomes are essential cellular structures involved in protein synthesis. The nucleolus is located within the nucleus of the cell and is involved in the assembly of ribosomal subunits. It contains DNA, RNA, and proteins necessary for ribosome production. Therefore, the nucleolus is the correct answer as it plays a crucial role in the synthesis of ribosomes.

The equation -iCRT is used to calculate solute potential. Solute potential refers to the effect of solute concentration on the movement of water. It is influenced by the number of solute particles (i), the gas constant (R), the temperature in Kelvin (T), and the pressure (P). This equation allows us to determine the solute potential, which is important in understanding the movement of water across membranes and in plant cells.

Starch is too large to pass through the proteins on the membrane of a cell, and Oxygen and Ethanol pass through the phospholipid bi-layer via passive transport and cannot be stopped.

The nucleus is surrounded by a double membrane. This double membrane is known as the nuclear envelope, which separates the nucleus from the rest of the cell. The nuclear envelope has two layers, an inner and an outer membrane, with a small space in between them called the perinuclear space. This double membrane acts as a protective barrier for the nucleus, allowing it to maintain its integrity and regulate the movement of molecules in and out of the nucleus.

The fluid mosaic model explains the variety of molecules found in the cell membrane. This model describes the cell membrane as a fluid structure composed of various molecules such as phospholipids, proteins, and cholesterol. These molecules are arranged in a mosaic pattern, allowing for flexibility and fluidity of the membrane. The model also explains how different molecules can move within the membrane, leading to the diverse functions of the cell membrane, such as selective permeability and cell signaling.

The main component of the cell membrane is a phospholipid. Phospholipids are a type of lipid that have a hydrophilic (water-loving) head and a hydrophobic (water-fearing) tail. These molecules arrange themselves in a double layer called the lipid bilayer, which forms the basic structure of the cell membrane. The hydrophilic heads face outward, interacting with the watery environment inside and outside the cell, while the hydrophobic tails face inward, creating a barrier that prevents the passage of certain molecules. Therefore, the correct answer is phospholipid.

Small nonpolar molecules will pass through a cell membrane most easily because the cell membrane is primarily composed of a lipid bilayer, which is impermeable to polar molecules due to its hydrophobic nature. Nonpolar molecules, on the other hand, can dissolve in the lipid bilayer and pass through it via simple diffusion. Additionally, their small size allows them to easily navigate through the membrane's hydrophobic core. Large polar molecules, large nonpolar molecules, and large neutral molecules would face more difficulty passing through the membrane due to their size and/or polarity.

Osmosis is the process in which fluid molecules move across a membrane from an area of high water concentration to an area of lower concentration. This movement occurs in order to balance the concentration of solute particles on both sides of the membrane.

When a membrane is permeable to both a solute and water, the solute and water molecules will move through the membrane in both directions until equilibrium is reached on both sides. This means that the concentration of solute and water will be the same on both sides of the membrane. After equilibrium is reached, there will still be movement of both solute and water, but there will be no net movement from one side to the other. This is because the concentrations are equal, so there is no driving force for further movement.

The Golgi bodies are responsible for the final processing of proteins. After proteins are synthesized in the endoplasmic reticulum and ribosomes, they are transported to the Golgi bodies. Here, the proteins undergo modifications such as folding, sorting, and packaging. The Golgi bodies also play a role in adding carbohydrate chains to proteins, forming glycoproteins. Therefore, the Golgi bodies are the organelles where the final processing and modification of proteins occur before they are transported to their final destinations within or outside the cell.

Endocytosis- General category of allowing molecules in via pockets of the cell membrane
Phagocytosis- Engulfing large particles by extension of the cytoplasm, specifically solid particles
Pinocytosis- Cell membrane folds in and forms a vesicle, takes in molecules like proteins
Exocytosis- expelling molecules by allowing vacuole with unwanted molecule to connect to membrane and open out of the cell (reverse of Endocytosis)

The blood plasma has a higher solute concentration (.1 M) compared to the white blood cell (.08 M). This makes the blood plasma hypertonic, meaning it has a higher concentration of solutes. In hypertonic solutions, water moves out of the cell in an attempt to equalize the solute concentration on both sides of the cell membrane. Therefore, water will move out of the white blood cell.