Anatomy and Physiology Chapter 3 - Intro to the Cell

cells are…

1. the building blocks of all organisms

2. derived from the division of pre-existing cells

3. the smallest units that perfomr all vital physiological functions

4. capable of maintaining homeostasis

cell theory

1. all living things are made of cells

2. the cell is the basic unit of life

3. cells arise from existing cells

cytology

the study of cells

sex cells

germ cells or reproductive cells

somatic cells

all body cells except sex cells

organelles in the cytoplasm

inner part of the cell, where many chemical reactions occur and subcellular components are suspended within

cytosol/cytoplasm

inner part of the cell, where many chemical reactions occur and subcellular components are suspended within; jelly-like

non-membrane organelles

direct contact with cytosol

cytoskeleton

internal protein framework that gives cytosol strength and flexibility

3 components of the cytoskeleton

1. microfilaments (actin)

2. intermediate filaments (various proteins)

3. microtubules (tubulin)

ribosomes

translate mRNA to proteins; makes polypeptide strands

free ribosomes

scattered around the cytoplasm

fixed ribosomes

bound to endoplasmic recticulum

proteasomes

contain protein digesting enzymes (proteases) to disassemble and recycle protein monomers (amino acids)

membranous organelles

separated from the cytosol by plasma membrane

endoplasmic recticulum

involved in synthesis, storage, transport, and detoxification

rough ER

has ribosomes; synthesizes and packages proteins

smooth ER

no ribosomes; synthesizes lipids and carbs

golgi apparatus

modifies things to be shipped within or outside of the cell; renews plasma membrane

lysosomes

vesicles with digestive enzymes produced by the golgi apparatus; break down food, old organelles, and invaders

autolysis

self-destruction of damaged or inactive cells and is done by lysosomes

peroxisomes

catalase inside breaks down fats and other organic compounds then neutralizes toxins created from this process (hydrogen peroxide); produced by other peroxisomes

mitochondria

double-membraned organelle taht creates most of the ATP in out bodies; contains their own DNA that tells them how to function and inherited from other mother

nucleus

stores genetic information

nucleolus

where ribosomes are made (rRNA)

chromatin

DNA packaged tightly together with proteins

nucleoplasm

like the cytoplasm, but in the nucleus

nuclear pores

holes on nuclear envelope that allow materials to pass through

nuclear envelope

double membrane that separates DNA from cytoplasm

plasma membrane

cell boundary that regulates passage of substances in and out of a cell; maintains structural integrity and is the cell’s largest organelle

4 functions of the plasma membrane

1. physical isolation

2. regulation of environmental exchange

3. sensitivity to environment

4. structural support

6 roles of the fluid mosaic model

1. transport

2. enzymatic activity

3. signal transduction

4. cell-cell recognition

5. intercellular joining

6. connecting to cell parts or extracellular matrix

4 parts of the endomembrane system

1. nuclear envelope (where transcribed DNA exits the nucleus)

2. endoplasmic reticulum (where proteins and lipids are synthesized)

3. golgi apparatus (where proteins and other molecules are refined, stored, and transported to other parts of the cell)

4. plasma membrane (maintains transport of things in and out of the cell; maintains cell structure)