Cells Flashcards
Living Structural and functional unit that is enclosed by a membrane
Cell
3 main parts of a cell
- Plasma membrane
- cytoplasm
- nucleus
Forms a cell’s flexible outer surface, separating the cell’s internal environment from its external environment
Plasma membrane
Regulates the flow of materials into and out of a cell to maintain the appropriate environment for normal cellular activities
Plasma membrane
Plays a key role in communication among cells and between cells and their external environment
Plasma membrane
Basic framework of plasma membrane?
- Lipid bilayer
- proteins
- Selectively permeable
What is the Lipid bilayer made up of?
Two tail to tail layers made up of phospholipids, cholesterol, and glycolipids
Two types of (membrane) proteins
Integral
peripheral
Protein that…
- extend through the lipid bilayer
- allow small and medium sized water-soluble materials to cross the membrane
Integral
Protein that…
- loosely attached to the exterior or interior surface of the membrane
Peripheral
Framework of plasma membrane that….
- allows some substances to move into and out of the cell but restricts the passage of other substances
Selectively permeable
Framework of plasma membrane that….
- not permeable to ions and large, uncharged polar molecules such as glucose and amino acids
Selectively permeable
[type of body fluid] fluid in body cells
intracellular fluid (ICF)
[type of body fluid] Fluid outside cells
Extracellular fluid (ECF)
[type of body fluid] ECF between cells in tissues
Interstitial fluid
[type of body fluid] ECF in blood vessels
Blood plasma
[type of body fluid] ECF in lymphatic vessels
Lymph
[type of body fluid] Surrounds the brain and spinal cord
Cerebrospinal fluid
[type of body fluid] Any material dissolved in a fluid
Solute
[type of body fluid] Fluid that dissolves materials
Solvent
Two methods for substances to move across the plasma membrane
Passive processes
Active processes
In this process, substance moves down its concentration gradient through the membrane, using only its own energy of motion (kinetic energy)
Passive processes
In this process, cellular energy, usually in the form of ATP, is used to “push” the substance through the membrane “uphill” against its concentration gradient
Active processes
movement of substances down a concentration gradient until equilibrium is reached; do not require cellular energy in the form of ATP
Passive process
Passive movement of a substance through the Lipid bilayer of the plasma membrane
Simple diffusion
Movement of substance by kinetic energy down a concentration graduate until equilibrium is reached
Diffusion
Passive movement of a substance down its concentration gradient aided by ion channels and carriers
Facilitated diffusion
Movement of water molecules across a Selectively permeable membrane from an area of higher water concentration to an area of lower water concentration
Osmosis
Movement of substances against a concentration gradient; requires cellular energy in the form of ATP
Active processes
Transport in which cells expends energy to move a substance across the membrane against in concentration gradient aided by membrane proteins that act as pumps; these integral membrane proteins use energy supplied by ATP
Active transport
Movement of substances into or out of a cell in vesicles that bud from the plasma membrane; requires energy supplied by ATP
Transport in vesicles
Movement of substances into a cell in vesicles
Endocytosis
“cell eating”; movement of a solid particle into a cell after pseudopods engulf it
Phagocytosis
“cell drinking ; movement of extracellular fluid into a cell by infolding of plasma membrane
Bulk-phase endocytosis
Movement of substances out of a cell in secretory vesicles that fuse with the plasma membrane and release their contents into the extracellular fluid
Exocytosis
Composed of a Lipid bilayer consisting of phospholipids, cholesterol, and glycolipids with various proteins inserted; surrounds cytoplasm
Plasma membrane
Protects cellular contents; make contact with other cells; contains channels, transporters, receptors, enzymes, and cell identity makes; mediates the entry and exit of substances
Plasma membrane
Cellular contents between plasma membrane and nucleus, including cytosol and organelles
Cytoplasm
Site of all intracellular activities except those occurring in the nucleus
Cytoplasm
Composed of water, solutes, suspended particles, Lipid droplets, and glycogen granules
Cytosol
Liquid in which many of the cell’s chemical reactions occur
Cytosol
A network in the cytoplasm composed of three protein filaments: microfilaments, intermediate filaments, and microtubules
Cytoskeleton
Maintains shape and general organization of cellular contents; responsible for cell movements
Cytoskeleton
Specialized cellular structures with characteristic shapes and specific functions
Organelles
Paired centrioles plus pericentriolar material
Centrosome
Motile cell surface projections with inner core of microtubules
Cillia and flagella
Protein synthesis
Ribosome
Site of synthesis of glycoproteins and phospholipids
Rough endoplasmic reticulum
Site of fatty acid and steroid synthesis
Smooth ER
Accepts proteins from rough ER
Golgi complex
Vesicle formed from golgi complex
Lysosome
Vesicle containing oxidative enzymes
Peroxisome
Tiny barrel-shaped structure that contains proteases, enzymes that cut proteins
Proteasome
Consists of outer and inner membranes, cristae, and matrix. Site of reactions that produce most of a cell’s ATP
Mitochondrion
Consists of nuclear envelope with pores, nucleoli, and chomatin (or chromosomes)
Nucleus
Contains genes, which control cellular structure, and direct most cellular activities
Nucleus
Within _______, chemical reactions of aerobic cellular respiration general ATP
Mitochondria
________ determine the physical and chemical characteristics of cells
Protein
Two steps in protein synthesis
Transcription, translation
- occurs in the nucleus
- generic information in the DNA base is copied into a complementary sequence of codons in a strand of DNA
- catalyzed by RNA polymerase
Transcription
Three kinds of RNA
Messenger RNA (mRNA)
Transfer RNA (tRNA)
Ribosomal RNA (rRNA)
Process in which mRNA associates with robisomes
Translation
Directs synthesis of a protein by converting the sequence of nucleotides in mRNA into a specific sequence of amino acid
Translation
Process whereby cells reproduce themselves
Cell division
As body cells become damages, diseased, or worn out, they are replaced by ______
Cell division
Two types of cell division
Meiosis, somatic cell division
Process that produces gametes - sperm and oocytes
Meiosis
Process where cells divides into two identical cells
Somatic cell division
Sequence of changes that a cell undergoes from the time it forms until it duplicates its contents and divides into two cells
Cell cycle
Two major periods of cell cycle
Interphase, mitotic phase
- when a cell is not dividing
- cell replicates its DNA
Interphase
- when a cell is dividing
- division of the nucleus and cytoplasm into two cells
Mitotic phase
Mitotic process is divided into 4 stages which are?
Prophase, metaphase, anaphase, telophase