Chapter 1 Flashcards
Cellular Structure and Function
Metabolism Definition
Sum of all chemical reactions taking place in an organism
Autotrophs Definition
Obtain energy from sunlight
Hetrotrophs Definition
Obtain energy from foods
Why Is growth necessary
For all living organisms to increase in size and for them to replace lost cells
Reproduction Definition
All living organisms need to replicate themselves in order to continue life
- Usually occurs with Variation
Asexual Reproduction Definition
Single celled organisms reproduce by dividing into two daughter cells
Sexual Reproduction
Most large organisms reproduce by means of special cells produced specifically for that purpose
Adaptation Definition
An organism possesses characteristics that enhance its survival and reproduction success in that particular environment
Living Organisms Definition
made up of one or more cells
Prokaryotic Cell Definition
Single Cells
- no nucleus (having a region called a nucleoid)
- no membrane bound internal compartments
- bacetria
small
Single Celled organisms Definition
Consist of only one cell
Eukaryotic Cell definition
Cells that contain true membrane bound nuclei. They also have other internal compartments that, like the nucleus are surrounded by membranes
Multicellular organisms structural levels of organisation
- chemical
- cell
- tissue
- organ
- system
Cell Theory
- All organisms are composed of cells
- All cells come from pre-existing cells
- Cells contain inherited information used in cell processes
- The cell is the smallest living organisational unit
Different types of Microscopes
- light microscopes
- electron microscope
- Scanning electron microscope (SEM)
- Transmission electron microscope (TEM)
Surface Area to Volume Ratio Definition
as an object gets bigger (its volume increases), the surface area in relation to that volume decreases
Surface Area to Volume Ratio Equation
Surface Area / Volume
Nucleus Definition
Control centre that regulates activities of the cell
Ribosomes Definition
- Involved in protein production
- Found in the endoplasmic reticulum or free floating in the cytosol
Endoplasmic Reticulum Location
connected to the nuclear membrane and sometimes cell membrane
Rough ER
- Covered in Ribosomes
- production, folding, quality control and despatch of some proteins
Smooth ER
- No Ribosomes attached
- produces lipids
- helps detoxify a number of organic chemicals
Golgi Apparatus
- located close to the endoplasmic reticulum
- packaging and storage of chemicals to be produced
Lysosomes
- vesicles that contain digestive enzymes
- found in cytoplasm
- digest foreign material
- break down organelles to be used as energy
- release their enzymes within the cell causing death of cell
Centriole
- small rod like structures
- visible when cell is undergoing cell division
- produces the spindles for mitosis
Cell Wall
- plant specific
- rigid structure that surrounds the outer membrane
- provided support
- composed of cellulose and lignin
Mitochondria
- site of aerobic respiration which produces energy
- Has DNA
- has an outer membrane and a highly folded inner membrane
Vacuole
- Plant Specific
- storage organelle
Plastids
storage organelles
- chloroplast
- Chromoplast
- Leucoplast
Phospholipid Bilayer Definition
- basic atom structure is made up of a double layer of phospholipid molecules
- forms a fluid mosaic
- made of lipids joined to phosphate groups
- hydrophilic heads are attracted to water
- hydrophobic tails repel water
Hydrophilic Head definition
- containing phosphate
- ‘water loving’
Hydrophobic Tail definition
- tail made out of fatty and side chains
- water repelling tails
Smallel Molecules - passing through phospholipid bilayer
- Oxygen, carbon, dioxide, water and urea can pass quickly though the pores as small molecules
Transport Proteins definiton
- have openings on both sides of the membrane, forming channels that allow substances to move through the membrane
Large Molecule - passing through phospholipid bilayer
- larger molecules are stopped or need assistance to pass through membrane
Receptor Proteins definiton
- Bind hormones and other substances that cause changes to the cell activities
- different types of cells have. different receptor proteins enabling them to carry out different functions
Recognition Proteins definiton
- attached to carbohydrate molecules and as as markers, called antigens which enable the immune system to distinguish between the body’s own cels and foreign invaders
Adhesion proteins definiton
- link cells together in multicellular organisms
Passive Process definiton
- Substances move down a concentration gradient from an area of higher to lower concentration or pressure
- the cell does not expend energy
What does the surface area to volume ratio affect in cells?
It limits cell size and necessitates internal compartments (organelles)
What are the distinct functions of chloroplasts and mitochondria?
Chloroplasts are involved in photosynthesis; mitochondria are involved in cellular respiration
What is the primary function of the plasma membrane?
To regulate the passage of substances via osmosis, facilitated diffusion, and active transport
What is the basic structure of the plasma membrane?
A phospholipid bilayer with embedded carbohydrates, proteins, and cholesterol
Define hydrophilic and hydrophobic.
Hydrophilic: water-loving; Hydrophobic: water-repelling
What types of substances can pass through the plasma membrane quickly?
Small and simple molecules like oxygen, carbon dioxide, water, and urea
What are transport proteins?
Proteins that form channels allowing substances to move through the membrane
What is the function of receptor proteins in the plasma membrane?
To bind hormones and other substances, causing changes in cell activity
What do recognition proteins do?
Act as markers (antigens) to help the immune system identify cells
What is facilitated diffusion?
The process where certain proteins assist the movement of larger molecules across the membrane
What are channel proteins?
Proteins that form pores in the membrane allowing water-soluble substances to pass through
What are carrier proteins?
Proteins that bind to diffusing molecules and transport them across the membrane
What is osmosis?
The diffusion of water across a selectively permeable membrane from higher to lower water concentration
What happens to animal cells in a hypertonic solution?
They shrink due to water loss
What happens to plant cells in a hypotonic solution?
They become turgid due to water uptake
What is active transport?
Movement of substances against a concentration gradient using energy
What is endocytosis?
Bulk movement of a substance into cell
What is phagocytosis?
Bulk movement of a solid substance into a cell
What is exocytosis?
Bulk movement of a substance out of a cell
True or False: Water is described as the universal solvent.
True
What is the significance of the sodium-potassium pump?
It maintains the resting membrane potential
Solute Definition
substance being dissolved
Solvent Definition
Another substance that does the dissolving
What is Pinocytosis?
Bulk movement of a solution into a cell
