Cells Unit 3 Biology Study Guide

Robert Hooke

first to observe and identify cells

Matthias Schleiden

discovered all plants have cells

Theodore Schwann

discovered all animals have cells

Rudolph Virchow

discovered all cells come from pre-existing cells and came up with cell theory

first rule of cell theory

all living things are made of cells

second rule of cell theory

the cell is the basic unit of structure and function in organisms

third rule of cell theory

all cells come from previously existing cells

type of microscope we use

compound

Compound Light Microscope

allow us to observe both living and nonliving cells, staining cells is required to be able to observe them

Electron Microscope

only nonliving cells/organisms can be seen; TRANSMISSION ELECTRON MICROSCOPE=study INTERNAL structure of cells and SCANNING ELECTRON MICROSCOPE=study SURFACE of cells & produce 3D image

Prokaryotic Cells

basic, oldest form of life, cells with no membrane enclosing the DNA ex: bacteria

Eukaryotic Cells

more complex, cells have a nucleus and other membrane bound organelles, you have these cells ex:plants, animals, fungi, and protists.

Basic Cell Parts

Plasma membrane, cytoplasm, ribosomes and genetic material (DNA or RNA).

organelles

the “organs” of the cell

cell membrane

surrounds and encloses the cell and regulates what enters and exits, made of phospholipids and proteins.

selectively permeable

allows nutrients, water, oxygen to enter, doesn’t allow toxins

Cytoskeleton

cyto=cell, skeleton of the cell and gives cell shape, main part of cytoplasm, made of microtubules, fibers & filaments

Nucleus

surrounded by a nuclear membrane, control center of the cell, holds the genetic material

Chromosomes

contains genes, made of long strands of DNA wrapped around proteins, visible only during cell division

Nucleolus

center of nucleus, makes ribosomes

Ribosomes

make proteins, found on Rough Endoplasmic Reticulum & Cytoplasm, made in nucleus, made of RNA

Endoplasmic Reticulum

network of membranes that specializes in making lipids & moving limpids, Rough and Smooth

Golgi Bodies

package products for secretion from the cell, add molecule markers that tell where each item needs to go ex: amazon; form vesicles that move to tell membrane & release contents outside of the cell

Lysosomes

have digestive enzymes that break down food molecules and old cell parts(proteins and lipids); called the “suicide sac” → release enzymes to break down the cell when it gets old

Vacuole

storage unit of the cell; contain enzymes, stores nutrients & waste products; regulates water content in cells

Mitochondria

“powerhouse of the cell”, releases energy from food molecules into a usable form for the cell, produces ATP, cells that need a lot of energy have many mitochondria

Centrioles (animal cells only!)

located outside of the nucleus, made of microtubules, important in cell division

Cell Wall (plant cells only!)

provides support & protection, outside of cell membrane, made of cellulose

Chloroplasts

hold chlorophyll which absorbs sunlight