ch2 Flashcards
What are cells?
Cells are the basic, living, structural and functional units of the body
The human body consists of more than 100 trillion cells.
What do cells perform to create life processes?
Chemical reactions
What are the three principal parts of a generalized cell?
- Plasma membrane
- Cytoplasm
- Nucleus
What is the structure of the plasma membrane?
Flexible yet sturdy barrier; fluid mosaic model
What does the fluid mosaic model describe?
The arrangement of molecules within the membrane resembles a sea of lipids containing many types of proteins
What role do lipids play in the plasma membrane?
Act as a barrier to certain substances
What are the types of proteins found in the plasma membrane?
- Integral proteins
- Transmembrane proteins
- Glycoproteins
- Peripheral proteins
What is glycocalyx?
A component of the plasma membrane
What are the functions of membrane proteins?
- Ion channels
- Carriers or transporters
- Receptors
- Enzymes
- Linkers
- Cell-identity markers
What is membrane permeability?
Cells are either permeable or impermeable to certain substances
What does selective permeability mean?
The ability of the membrane to allow certain substances to pass while blocking others
What are the types of body fluids involved in transport?
- Intracellular fluid (ICF)
- Extracellular fluid (ECF)
- Interstitial fluid
- Plasma
- Lymph
What are the two classifications of transport processes?
- Passive processes
- Active processes
What is facilitated diffusion?
A type of transport by transporter proteins
What are the three types of endocytosis?
- Receptor-mediated endocytosis
- Phagocytosis
- Bulk-phase endocytosis (pinocytosis)
What is exocytosis?
A process where materials are expelled from the cell
What are the two components of the cytoplasm?
- Cytosol
- Cytoskeleton
What are organelles?
Specialized structures within the cell that have specific shapes and functions
What is the function of ribosomes?
Sites of protein synthesis
What are the two types of endoplasmic reticulum?
- Rough ER
- Smooth ER
What is the role of the Golgi complex?
Processing and packaging proteins
What do lysosomes contain?
Digestive enzymes
What is Tay-Sachs disease associated with?
A deficiency in lysosomal function
What are mitochondria known as?
The powerhouses of the cell
What features do mitochondria have?
- External membrane
- Internal membrane
- Cristae
- Matrix
What is the nucleus?
Spherical or oval-shaped structure usually the most prominent feature of a cell
What components make up the nucleus?
- Nuclear envelope
- Nuclear pores
- Nucleolus
- Genes
- Chromosomes
What are the two types of cell division?
- Somatic cell division (Mitosis)
- Reproductive cell division (Meiosis)
What is the cell cycle comprised of?
- Interphase
- Mitotic Phase
What is cellular diversity?
Considerable variation in shapes and sizes of human cells
What are telomeres?
Structures that protect the ends of chromosomes
