Chp 3 Flashcards
Cell Theory (3 parts)
All organisms are composed of cells
Cells are the smallest living things
Cells arise only from pre-existing cells
Prokaryotic cells (bacterium)
smaller, simpler in structure
DNA concentrated in nucleoid region, not separated from rest of cell by membrane
Lacks most organelles
Eukaryotic Cells
Larger, more complex
Nucleus enclosed by membrane
Contains many types of organelles
3 Basic parts of all human cells
Flexible outer boundary
Intracellular fluid containing organelles and structural fibers
Control center
Average adult human is composed of how many cells?
64-100 trillion cells
Why is cell size limited?
It is easier to move chemicals/”things” within and out of a small cell
Average cell size
10μ (micrometers)
Nucleolus
Found within nucleus, site where all chromosomes are condensed. Area where ribosomes are assembled
Nucleus
Largest organelle,surrounded by nuclear envelope. Contains DNA and controls cell, makes proteins
RIbosomes
Made of small and large subunit. Function to build proteins through translation process
Vesicle
Membrane-bound container, moves materials around
Rough ER
Transport system, canals and channels that connect membrane to nucleus and to organelles within cell. Folded membrane that is continuous with the nucleus and is studded with ribosomes. Secretory pathway of protein synthesis
Smooth ER
continuous with the rough ER,
In liver: produces lipids and cholesterol, is important for detoxification. Synthesizes steroid based hormones
In intestinal cells: absorption, synthesis, transport of fats
Skeletal and cardiac muscle: storage and release of Ca
Golgi Body
Folded, looks like a pita pocket/stack of flattened membranes and vesicles. Modifies proteins and is like a shipping center of the cell
Cytoskeleton
Made of microtubules and microfilaments, provides physical structure to the cell. Anchors organelles, helps move substances. Cell motility (cilia, flagella) Muscle contraction and cell division
Mitochondria
Look like bacteria, made of a membrane folded inside another membrane. Mitochondria has its own DNA. Produces ATP for the cell through cellular respiration
Cytosol
Fluid within a cell that contains dissolved material, maintains concentration gradients within cell
Lysosomes
Small sacs filled with digestive enzymes. Essential to process of apoptosis “cell suicide” and are used to break down/digest material
Centriole
Part of the centrosome, important for positioning within the cell, determine where nucleus will be. During cell division the centriole initiates formation of the spindle.
Plasma membrane (fluid mosaic model)
separates intracellular fluids from extracellular fluids. Semipermeable. Double layer of phospholipids with embedded, dispersed proteins, glycolipids, and cholesterol.
Functions of membrane proteins
- Ion channels
- Carriers (transporters)
- Receptors
- Enzymes
- Intercellular joining (linker)
- Cell identity marker
Cytoplasm
Viscous fluid between plasma membrane and the nucleus: cytosol + organelles +interconnected filaments and fibers
Chromosomes
46 total (2n = 46, n = 23) Made of DNA and proteins, contains genes
Mitochondrial myopathy
Neuromuscular disorder due to malfunctioning mitochondria. Muscle weakness, muscle cramping, fatigue, lack of endurance, poor balance.
Mitosis
nuclear division
Cytokinesis
Cell division (Follows mitosis)
Interphase
most cells are in; growth phase, differentiation occurs
Life Cycle of CEll
IPMAT: interphase, prophase, prometaphase, metaphase, anaphase, telophase and cytokinesis
Cell specialization/differentiation
Process by which generic cells develop into a specific kind of cell
Cell Diversity, structure-function relationship
Red blood cells are flat, have a lot of surface area for gas exchange. Sperm cells have flagella that enables them to swim long distances to reach egg. Nerve cells can be a meter long, this length allows transmission of nerve signals/information from spinal cord to toe, for example. Fat cells are designed to store nutrients.
Mitochondria: failure of a single organelle can affect health
Mitochondrial myopathies: neuromuscular disorders due to malfunctioning mitochondria; muscle weakness, muscle cramping, fatigue, poor balance; can cause death
Fluid Mosaic Model
plasma membrane, separates intracellular fluids from extracellular fluids
Plays dynamic role in cellular activity, semipermeable
Glycoproteins
Cell-identity markers, distinguish your cells from anyone else’s. Includes Major Histocompatability proteins
Phospholipids
Form 75% of the lipid bilayer; hydrophilic heads, hydrophobic tails
Microtubule
Support the cell and give it shape; form centrioles and cilia and flagella (if present)
Microfilament
Involved in muscle contraction, help form cytoskeleton
What are cell membranes made of?
Double layer made of phospholipids, embedded proteins, glycolipids, and cholesterol
How are peripheral and integral proteins different?
Integral proteins are firmly inserted into the lipid bilayer. Peripheral proteins are not embedded, loosely attach to integral proteins.
6 Major Functions of the cell membrane
- Ion channels
- Carriers (transporters)
- Receptors
- Enzymes
- Intercellular joining (linker)
- Cell identity marker
