Cell or Plasma Membranes

No, ribosomes do not have cell membranes. Ribosomes are organelles responsible for protein synthesis in cells and are made up of ribosomal RNA and proteins. They are typically found floating freely in the cytoplasm or attached to the endoplasmic reticulum.

When ions move across a plasma membrane, it can create changes in membrane potential and can trigger physiological responses within the cell. The movement of ions is essential for functions such as nerve signaling, muscle contraction, and maintaining osmotic balance. Transport of ions across the membrane is tightly regulated to maintain cellular homeostasis.

Water moves into a membrane-bound hypotonic vesicle through the process of osmosis. In a hypotonic solution, the concentration of solutes outside the vesicle is lower than inside, causing water to flow into the vesicle to balance the concentration gradient.

Cell walls hold cells stiff so trees can grow tall. Cell membranes are flexible so animals can bend and move about. No tree can scratch itself where it itches. There is a disease that makes people so stiff they can not move. That would happen to everyone if they had cell walls.

Proteins are often found embedded in the cell membrane. These proteins are called transmembrane or inter-membrane proteins.

Cholesterol molecules are also found embedded in the hydrophobic interior of the cell membrane in many species

simple diffusion, a passive process where molecules move from an area of higher concentration to an area of lower concentration. This allows gases to move across the plasma membrane to maintain equilibrium between the cell and its surroundings.

False. Steroid hormones are lipophilic molecules that can pass through the plasma membrane of target cells. Once inside the cell, they bind to specific receptors located in the cytoplasm or nucleus, leading to changes in gene expression and cellular responses.

Cellulose, which is a carbohydrate found in the cell walls of plants, would not be found in an animal plasma membrane. Animal plasma membranes primarily consist of phospholipids, cholesterol, and proteins.

There are two layers of phospholipids in the plasma membrane, with each layer composed of phospholipid molecules arranged in a bilayer structure. This bilayer provides the membrane with its characteristic flexibility and semi-permeability.

The cell membrane is made up of a phospholipid bi-layer (a phospholipid has a polar head, and two non polar tails). the membrane's structure makes it so that the heads are opposite each other, and their tails intertwine, so it look like this:

( ) ( ) ( ) ( ) ( ) <-- polar heads

| | | | | | | | | | | | | | | | | |

| | | | | | | | | | | | | | | | | | <-- 2 non polar tails

| | | | | | | | | | | | | | | | | |

( ) ( ) ( ) ( ) <-- the other side of the membrane (polar heads)

the spaces that the tails create keep the membrane's fluidity.

The endoplasmic reticulum packages and ships products to the plasma membrane, outside the cell, or to other organelles through vesicles. These vesicles bud off from the endoplasmic reticulum and travel to their destination to deliver their cargo.

While all cells have cell membranes, action potentials are mainly generated by excitable cells like neurons and muscle cells due to the presence of voltage-gated ion channels. These channels allow for rapid changes in membrane potential, leading to the generation of action potentials. Non-excitable cells do not typically generate action potentials.

it helps control what goes in and out of the cell. It also help protect the nucleus, and the inside of the sperm.

The nuclear membrane is double-layered to provide additional protection and support for the delicate genetic material within the nucleus. This extra thickness helps to regulate the movement of molecules in and out of the nucleus, ensuring proper functioning of the cell.

Large molecules like proteins and nucleic acids have difficulty crossing the plasma membrane due to their size. Charged molecules or ions also face barriers crossing the membrane because of the hydrophobic nature of the lipid bilayer. Additionally, molecules that are not lipid-soluble may have difficulty passing through the membrane.

aniamal cells are eukaryotic cells meaning that they have a nucleus and other membrane bound organelles. One particular organelle is the mitochondria which produces mostt of the ATP for eukaryotic cells. Prokaryotes do not have a mitochondria so they must process ATP anaerobically in the plasma membrane via fermentation

Again the main reason behind this is the absence of electron transporting complex proteins in the plasma membrane of eukaryotic cells which are present in prokaryotic cells as well as in inner mitochondrial membrane. If there would have been the same complex as in prokaryotes then may be the mitochondrioa would have been of no use.

Substances that can freely dissolve through the plasma membrane are generally small and nonpolar molecules, such as oxygen, carbon dioxide, and ethanol. These molecules are able to pass through the lipid bilayer of the plasma membrane without requiring a specific transport protein.

The plasma membrane is made of phospholipids. Phospholipids contain a hydrophillic head group which is considered water soluable. They also contain a hydrophobic tail group whichi s considered lipid soluable

Yes a plant cell membrane acts as a barrier and controls what comes in and what leaves a plant. Many people get it confused with a cell wall but a cell wall keeps the plants shape, and a membrane controls the chemicals.

No, cell membranes in plants are not made of cellulose. Cellulose is a polysaccharide found in the cell walls of plants, providing structural support. The cell membrane, also known as the plasma membrane, is primarily composed of lipids and proteins and acts as a selective barrier regulating the passage of substances in and out of the cell.

One function of protein molecules in cell membranes is to transport molecules in and out of the cell. These proteins act as channels or carriers that help regulate the movement of substances across the membrane.

Cholesterol is the major chemical that functions to stiffen cell membranes and regulates the fluidity of animal cell membranes. It helps maintain membrane structure and integrity by reducing the movement of phospholipid molecules.

The plasma membrane specializes in controlling the movement of substances in and out of the cell through selective permeability. It also plays a role in cell communication and recognition through protein receptors embedded in the membrane. Additionally, the plasma membrane helps maintain the cell's shape and structure.

1. Phospholipid bilayer: Consists of two layers of phospholipid molecules that form the basic structure of the membrane.
2. Proteins: Act as channels for transporting molecules in and out of the cell, as well as receptors for cell signaling.
3. Cholesterol: Helps maintain the fluidity and stability of the membrane.