WGU D312 AP SEC 1, LESSON 2

WGU D312 AP SEC 1, LESSON 2

Cell Types

Somatic Cells

 Epithelial cells: form protective barriers on body surfaces

 Blood cells: include red and white blood cells with specific functions

 Osteoblasts: responsible for forming new bones

 Fibroblasts: provide structural framework for body tissues

 Muscle cells: include skeletal and smooth muscle cells

 Nerve cells: transmit messages within the nervous system

Germ Cells

 Parent cells of ova and sperm cells carrying genetic information across generations

Cell Organelles

Overview

 Membrane-enclosed structures with specific cell functions

Major Organelles

 Nucleus: central organelle containing DNA

 Cytoplasm: jelly-like substance housing organelles

 Cell membrane: thin barrier separating intracellular and extracellular fluids

 Mitochondria: powerhouse of the cell for ATP production

 Endoplasmic reticulum: network important for protein and lipid synthesis

Cytoplasmic Organelles

 Ribosomes: responsible for protein synthesis

 Golgi complex: prepares protein and fat molecules

 Lysosomes: contain digestive enzymes for cell waste breakdown

,  Mitochondria: involved in ATP production and storage

Cell Components

Cytoplasmic Components

 Cytoplasm: everything between cell membrane and nucleus

 Cytosol: aqueous part of cytoplasm where organelles are suspended

 Nucleoplasm: fluid within nucleus storing DNA

 Nucleoli: bodies containing genetic materials in the nucleus

 Chromatin: bead-like structure in chromosomes with DNA and protein

Membrane Components

 Nuclear envelope: double membrane separating nucleus from cytoplasm

 Selective permeability: membrane function allowing specific substance passage

 Hydrophilic: water-loving property

 Hydrophobic: water-repelling property

 Active transport: energy-requiring movement of solutes across membrane

Cell Transport Mechanisms

Passive Transport

 Diffusion: passive movement from high to low concentration

 Simple diffusion: no membrane protein assistance required

 Facilitated diffusion: needs membrane proteins for particle movement

 Osmosis: water movement across a semipermeable membrane

Active Transport

 Primary active transport: uses carrier proteins against concentration gradient

 Secondary active transport: utilizes stored energy to move substances

 Gradient: difference in substance concentration across a membrane

Cell Division

Types of Cell Division