Biology Unit 2 – Cells Questions and Answers 100% Pass

Biology Unit 2 – Cells Questions and Answers 100% Pass Prokaryote very small single celled organism that does not have a nucleus; bacteria eukaryote large cells that have a nucleus and form multicellular organisms; plants, animals, fungi and protists chloroplast an organelle found in plant cells where photosynthesis occurs cell wall strong layer around the cell membrane in plants, algae, and some bacteria vacuole cell organelle that stores materials such as water, salts, proteins, and carbohydrates virus DNA surrounded by a protein shell that must invade another cell and use a host cell's machinery to reproduce itself cell the basic unit of life organelle small structures inside a cell with specific functions Cell membrane regulates materials entering and exiting the cell. cytoplasm all cell contents that lie between the cell membrane and the nucleus (organells + cytosol) nucleus membrane bound; contains DNA; regulates DNA & RNA actions nuclear envelope regulates what enters or exits the nucleus; made of a double layer of lipids nucleolus organelle inside the nucleus; produces RNA, which is used to make protein DNA Deoxyribonucleic acid; information on how to make protein chromatin unorganized DNA chromosomes organized DNA Endoplasmic Reticulum Transportation route for Proteins; tubes and channels Ribosomes makes proteins; small circular organelles Vacuoles storage for water, nutrients, or waste; small membrane-bound organelle. Lysosomes Packets of enzymes that break down materials in a cell; small membrane-bound organelles mitochondria produce energy for the cell-site of cellular respiration; "Powerhouse"; double membrane-bound, kidney shaped Golgi Apparatus Packages, labels, and ships proteins out of the cell; pancake-shaped layered organelle cytoskeleton Provides support and structure for the cell; tubules Centrioles microtubules that help divide the cell during cell division; tubules Cilia many short fibers that provide movement for the cell flagella one long fiber that provides movement for the cell selectively permeable the cell membrane will only allow some things to enter or exit. phospholipid bi-layer 2 rows of lipids that form most of the cell membrane hydrophilic part of the cell membrane that loves water (head portion) hydrophobic part of the cell membrane that hates water (tails portion) Polar charged particles (example=water) non-polar not charged particles (example=lipids) channel proteins transport proteins in the cell membrane that act as a gate for polar and charged molecules . receptor proteins transport proteins in the cell membrane that bind a specific kind of molecule and let it cross. marker proteins proteins found on the cell membrane that identify the cell for the immune system to recognize it membrane proteins channel in the cell membrane - into and out of the cell fluid-mosaic model description of teh cell membrane structure. 'fluid' = constantly moving, 'mosaic' = made of many parts passive transport molecules move through the cell membrane from high to low cocentrations; NO energy is required. Diffusion passive transport where molecules move through the cell membrane from high to low cocentrations osmosis passive transport; diffusion of WATER facilitated diffusion passive transport; diffusion with the help of channel proteins; usually because molecules are too big or have a chaarge. hypertonic more 'stuff' and less water are outside the cell, water moves OUT of the cell; cell becomes shriveled; form of passive transport hypotonic less 'stuff' and more water are outside the cell, water moves INTO the cell; cell swells; form of passive transport isotonic same amount of 'stuff' and water on both sides fo the cell membrane; no movement; form of passive transport active transport molecules move through the cell membrane from low to high cocentrations; energy IS required. protein pumps Active transport by proteins in the cell membrane. endocytosis Active transport of large particles INTO the cell, by surrounding them with the cell membrane exocytosis Active transport of large particles OUT of the cell, by surrounding them with the cell membrane