Mitochondrial Cristae and Energy Production

Study Notes

Many foldings of the inner membrane form shelves with attached oxidative enzymes
Inner cavity (matrix) contains dissolved enzymes that extract energy from nutrients
Enzymes in the matrix work with oxidative enzymes on the shelves to oxidize nutrients, forming CO2 and water, and releasing energy
Liberated energy is used to synthesize ATP, which is then transported out of the mitochondrion and diffuses to release energy where needed for cellular functions

Nucleus contains large quantities of DNA (genes)
Nucleus is the control center, directing cell activities
Nuclear membrane is a double bilayer membrane, continuous with the endoplasmic reticulum, with numerous nuclear pores
Chromatin (condensed DNA) is found in the nucleoplasm
Nucleolus is an accumulation of RNA and proteins, not membrane-delimited, and functions to form ribosomal subunits
Nucleolus enlarges when the cell is actively synthesizing proteins

Simple diffusion: down an electrochemical gradient, not carrier-dependent, no metabolic energy required, and passive
Facilitated diffusion: down an electrochemical gradient, carrier-mediated, more rapid than simple diffusion, and passive
Primary active transport: against an electrochemical gradient, requires direct input of metabolic energy (ATP), and carrier-mediated
Secondary active transport: co-transport

Na+, K+-ATPase (Na+–K+ pump) transports Na+ from intracellular to extracellular fluid and K+ from extracellular to intracellular fluid, maintaining low intracellular [Na+] and high intracellular [K+]
Site of lipid synthesis: phospholipids and cholesterol

Membrane composition similar to smooth ER and plasma membrane
Composed of 4 or more stacked layers of flat vesicular structures
Receive transport vesicles from smooth ER and process substances to form lysosomes, secretory vesicles, and cytoplasmic components

Formed from budding Golgi apparatus
Contain hydrolytic enzymes (acid hydrolases) for intracellular digestion of damaged cellular structures, food particles, and unwanted matter
Fuse with pinocytotic or phagocytic vesicles

Similar to lysosomes but formed by self-replication or budding from smooth endoplasmic reticulum
Contain oxidases (hydrogen peroxide and catalase) to oxidize poisonous substances (e.g., alcohol)