Unit 1- Chapter: 3 Cells and Their Function

Cells

basic units of all life, organized, metabolizes, homeostasis, grows, moves, responds, and reproduces

Cytology

the study of cells

cyt/o

cell

Who discovered Microorganisms?

Antony Van Leeuwenhoek (1632 - 1723), first person to observe and describe micro-organisms accurately.

Compound Light Microscope

most commonly used in labs, uses visible light and 2 lens, magnifies up to 1000x

Transmission Electron Microscope (TEM)

Uses an electron bean instead of visible light, magnifies up to 1 million times, highest magnification of all microscopes

Scanning Electron Microscope (SEM)

shows surface features in 3D, magnifies up to 100,000 times

Plasma Membrane

outer limit of the cell, functions include: enclose the cell, participates in cell growth, reproduction, interaction between cells, regulates what goes into and comes out of the cell

Components of the Plasma Membrane

bilayer of phospholipids

Microvilli

short extensions in the membrane, absorbs materials, and found on cells in small intestines and kidneys

Nucleus (“small organ”)

control center of the cell, chromosomes live here, contains DNA, surrounded by nuclear membrane

Nucleolus

inside the nucleus, assembles the ribosomes which are a necessary in the production of proteins

Cytoplasm

colloidal suspension inside the cell from the nuclear membrane to the plasma membrane, support the organelles

Cytosol

is the liquid part of the cytoplasm, contains nutrients, minerals, enzymes, and water

Endoplasmic Reticulum (ER)

network of membranes, found in cytoplasm

reticulum

means (network)

endoplasmic

(within the cytoplasm)

Smooth ER

synthesis of lipids

Rough ER

has ribosomes attached, manufactures proteins

Mitochondria

“power plant” of the cell”, large organelle, round or bean-shaped. Energy from nutrients is changed into ATP

Mitochondrial DNA

found in the mother’s egg, used in cloning, used to identify family lines

Golgi Apparatus

stack of membrane sacs, sorts and modifies proteins, packages proteins for transport out of the cell, “UPS of the cell”

Lysosomes

contains digestive enzymes, breaks down carbs, proteins, lipids and nucleic acids, Removes waste and foreign materials

Autophagy

help destroy old and damaged cells then recycles them

auto

means (self)

phagy

means (eat)

Autolysis

cells self-destruct using enzymes inside the lysosomes

lys/o

means (dissolving, separating)

-some

means (body)

Peroxisomes

contains enzymes that break down toxic substances, ie drugs alcohol, free radicals

Vesicles

membrane-bound sacs, used for storage, lysosomes and peroxisomes are also vesicles, used to move material into and out of the cell. Your cell’s PODS container.

Centrioles

Rod-shaped organelle found near the nucleus, helps organize the cell during cell division. Separates chromosomes during cell division

Cilia

project from the cell surface, Hair like structures, wave movement of fluids around the cell. “Nose hair, eyelashes”

Flagellum

Whip-like extension from the cell surface, used to move the cell within fluid. Male sperm is the only normal human cell with flagellum

Cell Structure like a Walled City- Plasma Membrane

The walls (plasma membrane) restrict traffic in and out of the city.

Cell Structure like a Walled City- Nucleus

The town office (nucleus) contains blueprints (DNA) for all city buildings.

Cell Structure like a Walled City- Lysosomes and Peroxisomes

Waste disposal plants (lysosomes and peroxisomes) deal with waste.

Cell Structure like a Walled City- Ribosomes, ER, Golgi Apparatus

Factories (ribosomes, ER, Golgi apparatus) produce materials necessary for the city to function.

Cell Structure like a Walled City- Vesicles

Vehicles (vesicles) move substances with the city.

Cell Structure like a Walled City- Mitochondria

Power plants (mitochondria) generate energy.

4 substances found within the plasma membrane?

Phospholipids, cholesterol, carbs, and proteins

Organelles

small organs in the cell

Why is the nucleus called the cell’s control center?

Contains the DNA

2 types of organelles used for movement and what do they look like?

Cilia, hair-like and wave. Flagella, looks like a tail and flips to move.

Type of substances that maintain the membrane potential.

Ions

Passive Transport Diffusion

Does not require cellular energy, constant movement of particles from region of higher concentration to a lower concentration (concentration gradient) until it reaches equilibrium (is the same)

Facilitated Diffusion

Uses transporters to speed up the process across the plasma membrane in the direction of the concentration gradient. Example, movement of glucose into the cell

Osmosis

Diffusion of water through a semi-permeable membrane, water moves to an area of greater solute concentration

Isotonic

fluids outside the cell have the same concentration as inside the cell

iso

means (same, equal)

Hypotonic

less concentration outside of the cell than inside; draws water into the cell, swell or explodes; hemolysis

hypo

means (beneath, below)

hem/o

means (blood)

Hypertonic

higher concentration outside the cell than inside; draws water out of the cell, shrink and shrivels (crenation)hu

hyper

means (above, excessive)

Filtration

Water and dissolved materials forced on one side of a membrane to go through, example, blood going through the capillaries using blood pressure as its force

Active Transport

requires cellular energy, moves particles against the concentration gradient

Endocytosis

bulk movement of materials into the cell, using vesicles

endo

means (within)

Phagocytosis

large particles are engulfed by the plasma membrane and moved into the cell

phag/o

means (to eat, ingest)

Pinocytosis

plasma membranes engulfs fluids

pin/o

means (to drink)

Exocytosis

bulk movement of materials out of the cell using vesicles

ex/o

means (outside, away)

Without proteins

there is no structure and function

Genes

subunits of chromosomes that carry our inherited characteristics and direct protein manufacturing

Deoxyribonucleic Acid

DNA, made up of 4 nucleotides, adenosine (A), thymine (T), guanine (G), cytosine (C). Also a sugar (deoxyribose) and a phosphate.

DNA Structure

double helix shape, alternating sugar and phosphate molecule make up the side rails, paired nitrogen bases (nucleotides) complete the steps. Nitrogen bases are paired A&G, G&C in different configurations (“AT a Georgia College”). Held together by hydrogen bonds.

RNA Structure

Ribonucleic acid, sugar is ribose. Single strand, nucleotides are the same as DNA except contains no thymine. Has uracil that matches up with adenine.

Role of RNA

DNA is a blueprint to imprint message on RNA, DNA splits in half and the messenger RNA (mRNA) reads the genetic code

Transcription

DNA code is transcribed into the mRNATr

Translation

code is translated into the ribosomal RNA (rRNA) and the transfer RNA (tRNA)

Meiosis

cell division of egg and sperm, cuts the chromosome number in half

Somatic Cell

all other cells in the body

Cell division of somatic cells is by

Mitosis

Stages of Mitosis- Interphase

Stage between one mitosis and the next, DNA uncoils, each strand takes on a matching strand creating 2 strands identical to the original, strands held together by centromere

Stages of Mitosis- Prophase

DNA returns to a tight coil, nucleolus and nuclear membrane start to disappear, 2 centrioles move to the opposite end of the cell

Stages of Mitosis- Metaphase

chromosomes line up across the center (equator) of the spindle fibers

Stages of Mitosis- Anaphase

centromere splits, duplicated chromosomes separate, move to opposite end

Stages of Mitosis- Telophase

parent cell becomes 2 daughter cells, all identical

What is cell suicide/programmed cell death called?

Apoptosis

inter mean

between

meta means

change

pro means

before, in front of

ana means

upwards, back, again

tel/o means

end