Exam 2 Flashcards
Plasma Membrane (Cell Membrane)
Composed of a phospholipid bilayer, which makes the membrane flexible and strong, forming the skeleton of the cell. Each phospholipid has a hydrophilic (water-loving) head and two hydrophobic (water-hating) tails. It is selectively permeable, which allows certain substances to pass and blocks others. The Microvilli increase surface area for absorption in certain cells.
Membrane Proteins
Channels, Transporters, Receptors, Enzymes, Linkers, and Cell Identity Markers
Cytoplasm
The material between the nuclear membrane and the plasma membrane. The storage and working area of the cell. Includes the cytosol (fluid portion) and organelles (specialized cell structures that perform different functions within the cell).
Nucleus
The nucleus is the largest organelle of the cell and acts as the command center (brain) of the cell. The nuclear membrane, also called the envelope, is the outer layer of the nucleus. Nucleoplasm is the space between the nuclear membrane and nucleolus, where DNA is located. The nucleolus, or ‘little nucleus,’ makes ribosomes.
Mitochondria
Referred to as the ‘power plant’ of the cell, it converts nutrients into the chemical adenosine triphosphate (ATP). ATP (Adenosine Triphosphate) is the usable form of energy for cellular processes.
Endoplasmic Reticulum
A network of membranes within the cytoplasm. The Rough ER has ribosomes attached and is involved in folding and sorting proteins. The smooth ER lacks ribosomes and is primarily involved in lipid synthesis.
Golgi Apparatus
The Golgi apparatus processes & packages proteins & lipid molecules. Transport vesicles bring molecules from the Rough ER to Golgi apparatus. Molecules fuse with Golgi membrane & are sorted based on destination.
Molecules undergo remodeling & modifications in Golgi cisternae. Modified molecules are secreted out of cell or sent to another organelle.
Lysosomes
Lysosomes use their digestive enzymes to degrade and remove waste materials and foreign substances from the cell. Lysosomes break down waste and foreign materials from the cell.
Ribosomes
Ribosomes are minute particles consisting of RNA and are involved in protein synthesis.
Mitosis
Produces somatic cells by having a parent stem cell give rise to two identical daughter cells, each with 46 chromosomes.
Meiosis
Produces gametes (egg and sperm) and cuts the chromosome number in half to prepare for the union of egg and sperm during fertilization, resulting in 23 chromosomes in each gamete.”
Interphase
The cell prepares for division by replicating its DNA before mitosis begins. Identical strands of DNA are held together at the centromere until they separate during mitosis.
Prophase
DNA strands coil into chromosomes. The nucleus and nuclear membrane disappear. Centrioles move to opposite poles and form the spindle.
Metaphase
Chromosomes line up across the center of the cell. Identical strands of chromosomes are held together at the centromere until they separate.
Anaphase
Centromeres split. Identical chromosomes move toward opposite centrioles.
Telophase
Chromosomes continue to move toward centrioles. A nuclear membrane forms around each group of chromosomes. The plasma membrane pinches off in the middle of the cell, forming two new identical daughter cells.
Membrane Transport
Plasma membrane - a gatekeeper for the cell. Lipid-soluble substances (like hormones and oxygen) pass through easily using diffusion. Water-soluble substances (like sugar and salt) need membrane proteins to get through.
Passive Movement
Diffusion
Facilitated diffusion
Osmosis
Filtration
Active Movement
Active transport
Endocytosis
Phagocytosis
Pinocytosis
Exocytosis