Ch3 Flashcards
Three regions of nucleus
Nuclear envelop (nuclear membrane)
Nucleoli
Chromatin
The three main regions of a cell
Nucleus
Cytoplasm
Plasma membrane
Types of cell membrane junctions
Tight junction
Desmosomes: anchoring junctions
Gap junction: neighboring cells are connected by hollow cylinders composed of protein (called connexons)
Roles of glycoproteins (glycocalyx) in a life cell
Determine a blood type
Act as receptor
Play a role in cell to cell recognition and interactions
Three major elements of cytoplasm
Cytosol
Organelles
Inclusions
Functions of Cytoplasmic organelles
Metabolic machinery
- mitochondria
- ribosomes
- endoplasmic reticulum
- gogi apparatus
- lysosomes
- peroxisomes
Function of mitochondria
Supply ATP: site of major synthesis of ATP
Function of ribosomes
Ribosomes are assembled in nucleoli
The actual site of protein synthesis in the cell
(Rough endoplasmic reticulum: the whole ribosome membrane combination)
Endoplasmic reticulum
Network within cytoplasm
It provides a network of channels for carrying substances (primarily proteins) from one part of the cell to another.
Rough ER: protein from ribosomes migrate
Smooth ER: lipid metabolism and detoxification
Gogi apparatus
Membranous sacs. Traffic detector for cellular proteins.
Majo functions: modify and package proteins
Package lysosomes that remains in the cell
Pinches off sacs containing proteins and phospholipid destined for a home.
Lysosomes
Membranous bag containing digestive enzymes
Peroxisomes
Membranous sacs containing powerful oxidase enzymes that use molecular oxygen to detoxify a number of poisonous or harmful substances: alcohol and formaldehyde.
Disarm free radicals (normal byproduct of metabolism) into water
What is the basic unit of life?
Cell
Explain the four concepts of cell theory.
- A cell is the basic structural and functional unit of living
- The activity of an organism depends on the collective activities of its cell
- According to the principle of complementary, the biochemical activities of cells are dictated by the relative number of their specific sub cellular structure
- Continuity of life had a cellular basis
List four elements that make up the bulk of living matter.
Carbon, hydrogen, oxygen, nitrogen
What is a diluted saltwater solution in our body that derived from the blood?
Interstitial fluid
How does Hooke’s “cell” differ from current meaning of cell?
Current cell mean that The smallest unit, the building block, of all living things.
Hike’ cells was observed from cork cells, which were empty chambers once inhabited.
According to the cell theory, what the organism can do depends on —.
What its cells can do
Define generalized cell
Cells have the same basic part, and there are certain functions common to all cells.
List structures of the nucleus, and explain the function of chromatin and nucleoli,
Structure of nucleus: nucleolus(nucleoli), chromatin, nuclear envelope
Function of nucleoli: sites where ribosomes are assembled.
Function of chromatin: during cell division to form two dtr cells, the chromatin threads coil and condense to a form dense, rodlike bodies called chromosomes.
Name three basic parts of a cell
Nucleus- control center of the cell
Plasma membrane-external barrier that regulates what enters and leaves the cell
Cytoplasm - the are where most cell activities occur
What is general function of nucleoli?
Site of synthesis of ribosomes
What is the meaning of generalized cell?
The generalized cell is a concept that describes organelles and functions common to all cells.
Describe chemical implosion of the plasma membrane.
Plasma membrane consists of two lipid layers arranged “tail to tail” in which protein molecules float. The proteins form a constantly changing pattern or mosaic. (The fluid mosaic model)
Most of the lipid portion is phospholipid and a substantial amount of cholesterols are found.
Phospholipid has hydrophilic heads and hydrophobic tails. The hydrophobic makeup of the membrane relatively impermeable to most water-soluable molecules. The cholesterol helps keep the membrane fluid.
Describe three types of cell junctions.
Gap junction: neighboring cells are connected by hollow cylinders compose of protein (called connexons).
Tight junction: impermeable junction that bond cells together into leakproof sheets.
Anchoring junction (desmosomes): anchoring junction scattered like rivets along the sides of abutting cells. They prevent cells subjected to mechanic stress (ie.skin) from being pulled apart.
Why do phospholipids (which from bulk of cell membranes) organize into a bilayer, tail to tail, in a watery environment?
Phospholipids have both polar and no polar regions. Polar aligned with polar( water and other polar molecules inside and outside the cell). Nonpolar aligns with nonpolar in the membrane interior.
External faces of some membrane proteins have sugar groups attached to them. What are three soles these sugar-coated proteins play in the life of the cell?
Act as receptors
Determine blood type
Play a role in cell-to-cell interactions
What is the special function of gap junction and tight junction?
communication and binding together, respectively.
What is function of smooth ER?
Cholesterols and fat synthesis and breakdown
Detoxification of drugs and pesticides
Thus liver and male testes have many smooth ER.
Which nuclear component contains your gene?
Chromatin
What organelle is abundant in phagocytes and known as the cell’s demolition ?
Lysosomes
Lysosomes membranous bags contain powerful digestive enzymes, which formed by ribosomes and packaged by Golgi apparatus.
How do the cytosol and the cytoplasm differ?
Cytosol is the liquid portion of the cytoplasm
Which two organelles are sacs of enzymes and what is the function of each organelle ?
Lysosomes : digestive enzyme - cell demolition, breakdown ingested bacteria, worn-out organelles, and dead cells
Peroxisomes ; oxidase enzyme -detoxification and disarm free radicals
Which two types of cytoskeletal elements are involved in cell mobility?
Microtubules and microfilaments(actin and myosin)
Which of cytoskeletal elements is the basis of centrioles? Of microvilli?
The basis of centrioles is microtubules; that of microvilli is a core of actin filament.
What is the major role of microvilli?
Microvilli increase cell surface for absorptive cells.
What is major role of cilia?
Move substances across the free cell surface.
What are two types of cells that connected body tissue?
Fibroblast and erythrocytes
What is the main function of neuron?
Receiving and transmitting messages
Neurons gather information and control body functions
What is solution?
Homogeneous mixture of two or more components.
What is solvent ?
Dissolving medium. The substance present in the largest amount in a solution.
Water is body’s chief solvent.
The components or substances present in smaller amount are called solutes.
What is the energy source for all types of diffusion?
Kinetic energy
What determines the direction of any diffusion process?
The concentration gradient
What are two types of facilitated diffusion and how do they differ?
A channel protein is an opening formed by membrane proteins for diffusion of certain small solutes.
A carrier protein undergoes shape changes that allow diffusion of a specific substance through the membrane.