BSI Lecture 1 Organelle Functions Flashcards
Plasma membrane
- selective barrier between internal and external environment
- composed of lipid bilayer; contains membrane proteins and cholesterol
Cytosol
fluid portion of cytoplasm that surrounds the organelles
Cytoskeleton
serves as a scaffold that helps to determine a cell’s shape and to organize the cellular contents
Actin
- subunit: actin protein
- controls cell structure/shape
- essential for movement of whole cells (cell crawling)
Intermediate filaments
- most durable
- provide cells with mechanical strength
- the proteins that make up intermediate filaments are cell-type specific
Microtubules
- subunit: tubulin
- grow and radiate out from the centrosome
- constantly dissembling and reassembling-very dynamic
- anchors organelles
- act as a guide for intracellular transport. Kinesin and dynein are two motor proteins that walk along the microtubules carrying cargo
- form mitotic spindle during mitosis
- form cilia and flagella
Nucleus
- location of DNA containing the majority of a cell’s genes
- controls cellular structure
- directs cellular activity
Nuclear envelope
- inner nuclear membrane which is in contact with nuclear lamina
- Outer nuclear membrane which is continuous with ER
Nuclear lamina
- filamentous network of protein (lamins) within nucleus
- binds to chromatin and inner membrane of nuclear envelope
- gives structural support to the nuclear envelope
Nuclear pores
- site of all traffic between nucleus and cytoplasm
Nuclear Pore Complex (NPC)
- composed of more than 50 proteins called nucleoporins
- small water-soluble molecules can freely diffuse through
- larger molecules (RNA, protein) are regulated
Nucleolus
- cluster of protein, DNA, and RNA within nucleus
2. Where transcription of rRNA genes and assembly of ribosomes occurs
Endoplasmic Reticulum (ER)
membranous sacs continuous withe outer membrane of nuclear envelope
Rough ER
- site of protein synthesis for transmembrane proteins, secretory proteins, and most proteins stored in the golgi apparatus, lysosomes, endosomes
- site of phospholipid synthesis
- site of glycosylation
Glycosylation
- promotes protein folding
- can make proteins more resistant to proteolysis
- plays a role in cell-cell recognition
- plays a role in cell-cell adhesion
- plays a role in cell signaling
Smooth ER
- site of fatty acid and steroid synthesis
- site of drug inactivation and detoxification of other harmful substances
- calcium storage
Golgi Apparatus
- modifies proteins (glycosylation)
- packages and transports proteins received from the rough ER (forms secretory vesicles for proteins to be exocytosed; forms membranes vesicles that ferry new molecules to plasma membrane; forms transport vesicles that carry molecules to other organelles)
- stack of membranous sacs (cis face and trans face)
Mitochondria
- energy production (ATP production)
- calcium homeostasis
- plays role in apoptosis (cell suicide)
- contains circular DNA with genes encoding some proteins that function in the mitochondrion
Lysosomes
- contain digestive enzymes
2. digestion of particles and organelles (autophagy), or other cells (phagocytosis)
Peroxisomes
contains enzymes that breakdown lipids and destroy toxic molecules by oxidation
Centrosome
- builds microtubules (component of cytoskeleton)
2. forms mitotic spindle during cell division
Levels of Body Organization
Chemical, Cellular, Tissue, Organ, Organ System, Organismal
Chemical Level: Element types?
Carbon, Calcium, Hydrogen, Nitrogen, Oxygen, Phosphorous, Sulfur
Elements come together to form what?
Macromolecules
Name the 4 types of macromolecules
Carbohydrates, Lipids, Proteins, Nucleic Acids
Cellular Level: 3 Facts
- Smallest living unit of the body
- Disease due to cellular processes gone wrong
- Drugs act at cellular level (binds to proteins and receptors)
Tissue Level: Define
Groups of cells work together to perform a particular function
Cellular Level: Define
Basic structural and functional unit of organism
Identify the 4 types of tissue
Nervous, Muscle, Connective, Epithelial
Organ Level: Define
A structure of two or more tissues working together
Organ Systems Level: Define
Group of related organs that have a common function
12 Organ Systems
Nervous, Muscular, Skeletal, Integumentary, Cardiovascular, Respiratory, Endocrine, Digestive, Urinary, Immune, Lymphatic, Reproductive
3 Components of Cytoplasm
Cytosol, Cytoskeleton, Organelles
Types of Cytoskeleton
Actin (Microfilaments), Intermediate Filaments, Microtubules
Actin: Composition?
Two-stranded filament made of actin protein.
