Animal cell structure Flashcards
Plasma Membrane
Selective barrier and maintains cell shape; Biological membrane is double layer of phospholipids and other lipids; External membrane surrounds cell
Nucleus
Place where DNA and chromatin are located; DNA synthesis and also transcription/mRNA processing
Nuclear envelope
Membranous layer surrounding the nucleus; double membrane, each with lipid bilayer
Nucleolus
Located inside of the nucleus; rRNA synthesis
Nuclear lamina
Maintain shape of nucleus; composed of proteins underneath nuclear membrane (intermediate filaments in animals)
Nuclear pores
Allow substances to get in and out of nucleus (mature mRNA)
Ribosomes
In ALL cells; translation/protein synthesis
3 locations: free in cytoplasm, in endoplasmic reticulum (rough), or Mitochondria/chloroplast
Not an organelle
Mitochondria
Cellular respiration and produce ATP for cell’s energy; has smooth external layer and folded internal layer into cristae; inner layer has two compartments: mitochondrial matrix and intermembrane space
Chloroplast
Organelle found in leaves and other green organs in plants; contain chlorophyll and various enzymes that fxn in photosynthesis; contains thylakoid and has stroma
Fxn is photosynthesis, light rxns in thylakoid
Prokaryotes can perform photosynthesis without chloroplasts
Thylakoid
membranous-sacs in chloroplast that stack to form granum
Stroma
fluid internal
Peroxisomes
Oxidize various substrates, create h2o2 and convert to water; perform rxns of different functions through metabolism
Cytoskeleton
network of fibers extending throughout cytoplasm; function is to organize cell’s structure and activities, anchoring some organelles and facilitating movement
Three types of fibers:
Microtubules
Microfilaments
Intermediate filaments
Microtubules
Hollow rods that help maintain shape of cell; 25 nm diameter 15 nm lumen; alpha and beta tubulin; chromosome movement, cell motility, and organelle movement are also fxns; interact with motor proteins and need ATP to move vesicle or organelle
centrosome
place where microtubules spread out from
Centrioles
Nine triplets of microtubules arranged in a ring
Flagella and Cilia
Fxn is movement; beating patterns are influenced by microtubules; Flagella beats like a snake (sperm) and cilia goes back and forth laterally; Cilia is not in prokaryotes; both share common structure (microtubules ensheathed by extension from plasma membrane), basal body to anchor, and motor protein of dynein which drives beating/bending movements
Microfilaments (actin filaments)
Two actin strands are intertwined, 7nm
1. Maintain cell shape
2. Change cell shape
3. Muscle contraction
4. Cytoplasmic streaming in plant cells
5. Cell motility
cytoplasmic streaming
circular flow of cytoplasm within the cell, driven by actin-myosin interaction (muscle contractions)
Intermediate filaments
fibrous proteins coiled into cables, 8-12 nm diameter; maintains cell shape, anchorage of nucleus and other organelles, and formation of nuclear lamina
Cell Wall
In plants and some fungi; protects cell, maintains shape, and prevents excessive uptake of water; Plant cell walls are made of cellulose
Primary Cell Wall
thin layer for young cell, flexible
Middle lamina
Thin layer between the primary layer and adjacent cells
Secondary Cell Wall
Added between plasma membrane and primary cell wall (thick and strong)
