Cytology

What is cytology?

Anatomy of the cell – Nucleus, DNA, Cytoplasm, Organelles

Aerobic and anaerobic respiration

Photosynthesis

Objectives

What does ‘cytology’ mean?

The study of the structure and function of cells

Basic StructureNucleus (eukaryotes)Cell membraneCytoplasm

CytosolOrganelles

Cytology

Basic StructureNucleus – control

centerCytoplasm – space

outside nucleus surrounded by cell membraneContains

Organelles – tiny structures which perform functions for the cell

Cytosol – fluid around the organelles

Types of CellsProkaryote

Smaller & SimplerConsidered “primitive”

Lack membrane-bound organelles

No nucleusFree floating genetic

materialBacteria

Types of CellsEukaryote

Membrane-bound nucleus

Membrane-bound organelles

Plant & animal cells

Eukaryotic Cell Anatomy

The NucleusControl center of cell

– in charge of everything Like the office of the

schoolContains DNA –

blueprints for making proteins and other essential compounds

Nucleolus – small, dense region where ribosomes are formed

Nuclear envelope – double layered membrane surrounding the nucleus

Nuclear pores – control what moves into and out of the nucleus

DNA – Deoxyribonucleic acid – genetic material of lifeChromatin – long chains of DNA stretched out

inside the nucleusChromosomes – short thick coiled up sections of

DNA

The Nucleus

Building blocks of DNA are called Nucleotides

Consists of a phosphate, sugar and a nitrogenous base4 types of nitrogenous base

adenine (A)thymine (T)cytosine (C)guanine (G)

DNA Structure

DNA consists of two nucleotide chains wound together to form a double helix

Nucleotide Structure

Watson & Crick1953

Discovered double-helix structureDiscovered complimentary base-pair rule

A – T C – G

Why ‘triplet’?Every group of 3 nitrogenous bases codes for

one of the 20 amino acids!

DNA

DNA Triplet

DNA Triplet

Organelles

Using your textbook or a laptop, research the function of each of the organelles list on the summary sheet.

Eukaryotic Cell Structure

Cell Anatomy

Cells Alive

How Big Are Cells?

Organelles

MitochondriaWhat do we know

about mitochondria?

Power plant for the cell

Site of cellular respiration

Has it’s own DNA!!!

Glucose gets broken down in the presence of oxygen to produce energy (exothermic or catabolic)

Carbon dioxide & water are the other by-products

C6H12O6 + 6O2 6CO2 + 6H2O + ENERGY

Releases lots of energy at a relatively slow, steady pace

Cellular Respiration

Glucose gets broken down without the use of oxygen (exothermic or catabolic)

Produces lactic acid = the “burn”

C6H12O6 2 C3H6O3 + Energy

Releases small amount of energy at a really quick rate

Anaerobic Respiration

Adenosine triphosphate

Converts energy to make it useful to the cell

Aerobic respiration produces enough energy that it requires 36 ATP molecules

Anaerobic respiration produces enough energy that it requires only 2 ATP molecules

ATP

Animal cell vs Plant cell; what’s the difference?

Contain special organelles called “plastids”

Chloroplasts – site of photosynthesis; contain green pigment (chlorophyll)

- contain thylakoid discs stacked into columns called granum (grana – plural)

Amyloplasts – found in root cells of plants and their function is to store starch

Plant Cells

Chloroplasts

Exact opposite reaction to cellular respiration

Carbon dioxide + water + energy (sunlight) = sugar (glucose) + oxygen

6CO2 + 6H2O + sun light C6H12O6 + 6O2

Endothermic/anabolic reaction

Photosynthesis

Cytology TestTBAReview Sheet

Use the text or ask questions