Objective: I will review Cell Structure and function for NJ ASK review by participating in a power point presentation, filling in a note-taking guide and answering NJ ASK questions.

Cell Structure & Function All living organisms on Earth are made up of microscopic structures called cells.  There are many types of cells, including plant cells and animal cells. Cells consist of smaller pieces, called organelles. Organelles are like the "organs" of a cell; they are groups of complex molecules that help cells survive. Different cells can have different organelles.

cytoplasm   is the suspension fluid that contains all of the organelles of the cell located between the nucleus and the cell membrane, as well as the support structures that help give the cell its shape.  It is also the site of most of the chemical reactions that take place in the cell. Cytoplasm is made up mostly of water.

Vacuole stores water and ingested food in a fluid sack and helps remove waste from the cell. the vacuoles found in animal cells are very small plant cells have one large, central vacuole.  The central vacuole in plants produces pressure against the cell wall (this is known as turgor pressure) for cellular support.

The cell membrane (or plasma membrane) acts as a boundary layer around the cytoplasm that separates a cell from its outside environment.  able to recognize chemical signals is selectively permeable to chemicals and controls which molecules enter and leave the cell.  Nutrients first enter the cell through the cell membrane

Nucleus The nucleus is the control center of the cell. It contains chromosomal information composed of long, thin strands of DNA that control cell metabolism and heredity.

ribosomes  The are RNA and protein complexes that are found in all cells.  These complexes help cells during protein translation by joining amino acids together to form polypeptides.

mitochondria  The take in nutrients, break them down and create energy (or ATP) for the cell.

endoplasmic reticulum  transports proteins within the cell.  It also makes lipids and several other materials used inside and outside of the cell.

The Golgi apparatus  processes and transports wastes (and other materials) out of the cell. processes, sorts, and modifies proteins in the cell.

Plant vs. Animal Cells While plant and animal cells share many organelles, there are a few organelles that are specific to plant cells. These organelles include the cell wall and chloroplasts. Unlike animal cells, plant cells have chloroplasts and a cell wall. The cell wall is a secretion of the cell membrane; it provides protection from physical injury and, with the vacuole, it provides structural support. Since it is made primarily of cellulose, it gives plant cells a structure that is more rigid than that of animal cells. The chloroplasts are the food producers in a plant cell. These small green organelles use energy from the Sun to produce glucose sugar in a process called photosynthesis. Both plants and animals use glucose as a source of energy.

Cell Functions Cells of multicellular organisms must grow and divide as the organism grows. This is because the size of individual cells does not change very much.  When an organism needs to grow bigger, it must make more cells. The body of a multicellular organism can also repair itself by using cell division to make more cells.

obtain nutrients  The cell membrane of a cell allows the cell to take in nutrients (or food molecules) while keeping out things that are bad for the cell.  Plant cells that contain chloroplasts can also make their own food by using energy from the Sun.

extract energy.   The mitochondria found in both plant and animal cells use nutrients to make ATP.  Cells use ATP as their main source of energy.

dispose of waste materials During waste removal, the cell membrane works with other cell organelles to move waste products from an area of higher concentration (inside the cell) to an area of lower concentration (outside the cell.)

Cells & Water All organisms need water to survive and to maintain normal functions.  Cells need water for most life processes, such as getting energy from food and transporting materials between cells.  The cells of all living things contain water. In fact, water accounts for about two-thirds of a typical cell's mass.

photosynthesis.  Plants receive their energy from the Sun in a process known as photosynthesis.  The cycle of photosynthesis combines water, carbon dioxide (the gas that humans and other animals exhale) and light energy to produce energy and oxygen.

osmosis Diffusion of water through a semi-permeable membrane

cellular respiration Animals go through a process of cellular respiration to receive energy from food

Single-celled & Multi-celled Organisms All living things contain at least one cell.  Single-celled organisms perform all of their life processes within a single cell, while multi-celled organisms can have specialized cells for different functions. Cells contain everything that is necessary for life. They have a variety of parts, and each part has a different set of functions. Cells may be part of a multi-celled organism, or they may be single-celled organisms.

Single-celled Organisms Single-celled, or unicellular, organisms may live alone or as part of a colony.  For single-celled organisms, each cell by itself can get food and air.  Many single-celled organisms can move themselves through their environments. Single-celled organisms can reproduce themselves, although some do reproduce sexually.

Multi-celled Organisms Multi-celled, or multicellular, organisms may have many different kinds of cells. Each kind of cell has its own purpose and specialized parts that help the cell to carry out its function. Cells from multi-celled organisms cannot survive on their own. The cells must work together in order to get food and air and to help the organism reproduce. Multi-celled organisms may be very small and made up of only a few cells, or very large and made up of trillions and trillions of cells. All plants and animals are multi-celled organisms.